I had just the opposite situation.
My father demanded that I take him in. He is 52, is severly overweight, diabetic, and is in a wheelchair since having a leg amputated last year. Neither my wife (of 8 months) nor I get along with him. He is imposing, still treats me like a child, is a pathological liar, and has a history of stealing from family.
Neither of our small bathrooms can be negotiated in a wheelchair, and because our house is a split-level, he would always be away from something he needs (bathrooms are above and below each other, the kitchen is on the ground-level floor). Further, despite strength training, there's no way I could carry a 375 lbs. man up and down stairs a few times a day. Not the least of all, I couldn't trust him to be left home alone. My father is a master of social engineering and could find a way to steal from me even if he couldn't physically get out of the house.
That being said, it seems like you have the ideal situation. The thing that concerns me the most is the response from your wife. In our case, above all else, we knew that our young marriage could not endure the stress of having my father around. You and your wife need to be of one mind on this, as this will affect you both every day. You need to ask your wife about what her reservations are, and determine together whether they can be addressed or if they are total show-stoppers. I've seen too many people (both husbands and wives) who get their spouse to capitulate on this issue and it only ends up breeding animosity and resentment.
That's my 2¢--which at today's exchange rates give you $0.00 USD.
