I worry about your going up and down the stairs because of the risk of falls. It seems doubtful to me to be able to safely go up and down stairs in a cast or with a knee scooter, walker, or wheelchair. Crutches are very iffy to do safely up and down stairs for a long time.

Would it be possible to temporarily move just what you really need to the ground floor, and live there until you can safely go up and down stairs?

How about getting a walking boot or a fake cast before the surgery so you can test wearing them and moving around your apartment to see what problems you have and to work them out in advance?

Sending good thoughts your way!