73 Rusted Duster

Hi! New here to Forabodiesonly, and actually new to A-bodies altogether! I figured i might be able to get a little help from the forum.
My aunt gave me a '73 225 Duster, and unfortunately the floors are pretty rusted out... I'm going to try and replace them, and i'm minutes from Summit Racing, so getting the part is no problem.

I was just wondering, do you think it would be possible to cut the floor out and replace it as one piece, with the engine, trans, driveshaft, dashboard, and steering wheel still in place? I already have the carpet and seats out of the car, all the way down to metal. I was thinking maybe I could pull the back windows out and get it in there. Or should i get the patch panels and do it that way? Is it even feasible to replace the floors with most of the car still together? I'm going to drop the gas tank, definitely.

Please help! I'd love to get this car back on the road. But these floors are holding me back.