Cycling and swimming should be your friend during this. I am in a similar situation although i am actually post surgery, it took me two years to get the surgery but that was more on me sitting it out to see what happened before finally going under for medial meniscus tear. I am 4 weeks out of surgery now and still far from fixed but cycling is part of the rehab protocol so for me lots of no resistance spinning and then slowly working up to more resistance. Lots of shallow squats are also good but not too much deep flextion for me but depends on where your tear is.
i am not yet convinced i have seen the last of the scalpel for this but as i am only 4 weeks out i will keep an open mind.
thanks for this - my PT told me today that things are looking pretty good for the time out i am, the main soreness seems to be from the portals but also some soreness to a greater or lesser degree towards the side/back of the knee which seems to be the 'operation site' as when the piece is taken out there is some vascular/nerve supply that takes a bit of time to settle.
For me since the OP stairs have been a real issue however these are starting to get easier, i think its more a mental battle about believing that you cant really damage the area by doing 'normal' things like walking and just getting on with it. I think its important to not baby it as i have found when i do my hip/knee on my 'good' side start playing up due to taking on too much which i know i have to avoid.
I am improving by the day so i hope that i can get back into things by week 4.