My mother had one done. She was moving same day, walking within a day (with a walker), and home from rehab in a few days. She didn't want to be in the rehab, so the mental portion is a lot of it. I wouldn't expect to be gardening and driving the next week, and since you live alone, rehab may be a prudent place to "camp out".
Hips are much easier than knees says my DPT wife. You want to be getting range of motion and bearing weight soon - waiting too long will make regaining anger more difficult later.
It's all about YOUR mentality going in, and how capable you are going in to care for yourself coming out. If you're in good health, light weight for your size, healthy, and have good balance and range of motion, you should be able to prove to the pt and ot that you're capable of leaving.
Good luck!