Re: put it off as long as possible.
It sounds like you have made a well-considered decision. I hope that your surgery and recovery go well! (I've had plenty of surgeries myself, but fortunately have not need a new knee.) I suggest taking very little with you to the hospital, just personal grooming items and something to wear home. Make sure that your wear-home outfit is easy to put on ("bad" leg first).
I would also bring an eye mask and a pair of earplugs. I got little sleep in the hospital, due to chatty family members and nurses in the hall outside my door.
If your hospital or doctor offers a TKR class, I would certainly attend it.