This is a great answer! You know what to do and how to do it!
It's sometimes difficult to think about accessibility. However, no one likes to miss out on spending time with friends, especially if they're recovering from an illness. Maybe next time you could research accessible movie theatres and see the great new movie there instead, where everyone can enjoy it!
You appear concerned that you injured friend using a wheelchair will not be able to participate in the group activity. Instead of postponing seeing the movie, you could find out what movie theatres are accessible so you won't have to miss out on seeing it!
You are really thinking about how to make this trip accessible for your friend and for everyone to enjoy their time together! If the movie theatre cannot make the space accessible for your friend, you could look for a more accessible movie theatre nearby.