Trying to buy a house

Having difficulty affording a house here in the Yukon. But I heard if I buy a house that has tenants already or I’m willing to rent out a room or two in the house then that could help me qualify for a larger mortgage. Anyway just wondering if it’s possible to find Yukoners who are willing to sign a rental agreement that is contingent on if the sale of the house is successful. It’s a 4 bedroom 3 bathroom house and I would be willing to rent the top floor out 3 bedrooms and two bathrooms, but will need access to the kitchen only since the house only has one kitchen. Would that be something possible or should I just give up trying to buy?