@routlaw
Don't give up so soon. My wife has had both hips replaced and both knees replaced.
She had the last knee done in 2024 on the day before Thanksgiving. (The first one 2 years before that one.) It takes a number of months to recover and it takes about a full year before you do not know it was done. She was told to expect to get 130 to 135 degrees of flex, not what you said.
You do need to keep up the PT to get the flex back, so do not stop PT and after the PT sessions are done you will probably need to do the exercises yourself at home if your muscles are still complaining. After a year, she was able to knee down, but uses a foam pad to knee on. So do not give up on the OTT and camping.
If you have any other questions, feel free to PM me and I can get you in touch with my wife.