NDP MPs are meeting this week in Saskatoon ahead of the now delayed return of Parliament. It's a site chosen with purpose since the province's federal riding boundaries have been redrawn, giving the social democrats a better chance at taking a seat in the province where the party was born.

NDP Leader Tom Mulcair is speaking to reporters in Saskatoon live at 3 p.m. ET.

"Location's important," NDP House leader Nathan Cullen said in an interview with CBC News.

"As many have said, we have many trees but shallow roots in Quebec, and deep roots and not any trees right now in Saskatchewan. But that's about to change. We have new boundary maps that make for a much more fair option and Saskatchewan's going to get some representation next election."

MPs will have lots to talk about, including an extended summer away from Parliament Hill: Prime Minister Stephen Harper announced last month that he intends to prorogue Parliament and have a throne speech to reset the government's agenda.

Harper will have to ask Gov. Gen. David Johnston to agree to the prorogation at some point before the House and Senate were originally due to resume on Sept. 16.

The meetings kick off Monday afternoon with regional caucuses, which are closed to the media. The main meetings begin Tuesday morning with a meeting with Saskatchewan NDP Leader Cam Broten, followed by a speech by Life of Pi author Yann Martel, and a fundraising event Tuesday night at a local bar.

NDP Leader Tom Mulcair will make his main speech to caucus on Wednesday, and former Saskatchewan NDP premier Roy Romanow will meet with the caucus shortly after. The agenda wraps up around 4:30 p.m. ET.

As MPs look to the fall session — and to the 2015 federal election — here are four themes to watch at this week's caucus meeting.

New boundaries, new hope

The new boundaries change the existing ridings to make some of them urban, as opposed to the more wedge-shaped boundaries used in the past that included both rural and urban parts. The shifts are likely to favour the NDP, which runs second to the governing Conservatives in the Prairies.

In an interview with CBC Radio's Susan Lunn on Sunday, Mulcair sounded confident about how the changes will affect the party's chances in 2015.

"We're convinced we're going to be taking the majority of the seats in Saskatchewan in the next election," he said in an interview with CBC.

"Whenever we're recruiting now, we're getting very strong candidates," he added.

Much of the focus will be on Nettie Wiebe, who lost the 2011 race for Saskatoon-Rosetown-Biggar to Conservative Kelly Block by about 550 votes. Block has already said she will seek the new rural-only riding of Humboldt-Warman-Martensville-Rosetown in 2015.

Block also won the riding in 2008.

Noah Evanchuk is another possible candidate to watch: Evanchuk came in second to Conservative MP Ray Boughen, losing by just over 700 votes in the Palliser riding.

Senate scandal a prime target

NDP MPs have continued the Official Opposition's focus on the Senate over the summer, travelling the country with the "Roll Up the Red Carpet" campaign. Cullen says the party isn't forgetting about the spending scandal that hit Conservative-appointed senators Patrick Brazeau, Mike Duffy and Pamela Wallin, and one Liberal-appointed senator, Mac Harb, who has since resigned from the Senate.

"The context for everything right now is that obviously the government is still reeling from scandal, a scandal of their own making," Cullen said.

"They've pushed Parliament off … somewhat indefinitely. Democracy's getting inconvenient for Mr. Harper and has been for a long time."

Conveniently for the NDP, the party has no representation in the Senate, making it an easy stick with which to beat the governing Conservatives and the opposition Liberals, who have third-party status but have nevertheless been leading in recent polls.

Speaking of whom ...

Liberal Leader Justin Trudeau grabbed headlines last month with his admission that he smoked pot while a sitting MP. He says he would push to legalize marijuana so its sale can be regulated. The NDP strategy so far has been to ignore him and the House's third party — Mulcair refused to say his name at the party's convention last April — but that's been increasingly hard, between Trudeau's knack for getting in the news and with both opposition parties trying to stake out territory among the same group of middle-class voters.

"Our focus overwhelmingly is the folks that sit across from us because they're the ones doing the damage to Canada. They're the ones, if you look at our path to government, it goes right through the Conservative Party of Canada," Cullen said.

It's easy, he says, to grab headlines by making controversial statements.

"But the problem becomes whether you're serious or not about running the country. And if you follow every shiny object, eventually you start running into a whole pile of contradictions. Because what's topical and headline-grabbing today is opposite to what you said six months ago and people start to notice."

"Because running a country is about more than grabbing a headline or two," Cullen added.

The economy

Last spring, the NDP took the emphasis off of the word socialism in the preamble to its constitution, voting to use a much longer preamble than the one created at the party's inception.

The new preamble, for which the vast majority of party members voted at the April convention, refers to seeking a future "which brings together the best of the insights and objectives of Canadians who, within the social democratic and democratic socialist traditions, have worked through farmer, labour, co-operative, feminist," and other movements.

It's all part of a move to cast the party as one that can handle managing the economy. It's something provincial NDP governments have shown, but remains an untested front for the federal NDP.

As part of that, Mulcair has been emphasizing middle-class Canadians and the economy in his criticism of the federal Conservatives. It's the same group of voters to whom Trudeau has been trying to appeal, making it a likely battleground in the march toward the next federal election.