The only one I can see for domestic travel that allows 2 people is the weekend transcon pass, but that is overkill destination-wise and both in Standard and weekend-only + 3 days advance purchase. The closest option to what OP is looking for, as described, would probably be PD's 20-credit PorterClassic Triangle-Western Canada passes, but I'm not sure if that would be a good deal compared to, say, last minute F8 bookings.

OP, if you do end up buying passes and have a MB (or any Western province for that matter) billing address for use, you'll be charged GST only instead of HST (or QST for Quebec).