At the same time, you'd be messing with some 'weight' issues of the house, if there's weight 'above' your cut.
Let's put it this way - How are you going to explain to your Insurance Company the reason the roof above your cut is now in the bedroom below? As Sparky already said, it ain't worth it.
Jay J -Moderator
PS: If you rent the saw, you don't think the blade is a new one, do you? You can BET that the paperwork will include a 'fee' for, or towards, blade replacement when you return. I guess you could tell the Rental Agency to keep the blade and you'd buy your own, but go and price one. I think that's the price a contractor would charge (as long as you do the clean-up.)