Thanks for clarifying, sounds like a routine meniscal repair which is good! well, relatively speaking of course!
Protocols will have him up and about in a few days so 2 weeks post op he should be feeling much better with minimal swelling. Depending on his ability to heal, an ECV would be great, he can simply transfer too and from the rides himself and have some time to be up and about without any pressure to walk all day. With the additional temperatures, I would make sure you have him ice it regularly, and potentially depending on how comfortable his surgeon is with it he could always asked for a low tapered dose of prednisone to help with the swelling or discomfort that may be caused by travel.
After 2 weeks you will have a good idea as to the range of movement he will have with regards to degree bend. Most people will be able to have good bend on a moderate repair after 2 weeks but everyone is different. He will also need to make sure he stays hydrated and don't be afraid to use any of his pain meds.