In reply to tcb:
FWIW, I was off climbing for a similar amount of time after a foot injury and ended up coming back with stronger fingers than before.
So: fingerboarding you're doing already, but if you're not able to do any actual climbing, you can crank up the intensity and frequency of sessions because you don't need to recover from the physical stresses of climbing itself.
Plus, all sorts of pull-ups, hanging leg raises, lever work, etc.
(Just watch out so you don't bash your foot if you drop off unexpectedly.)
Gym stuff: when I was on crutches, I found that *getting* to a gym was way too much hassle (I don't have a car). But if you've got a few weights at home, you can do a tonne of stuff. This is also a good time for any rehab/prehab exercises that you may have been ignoring -- e.g. if your elbows can be a bit tweaky, now's the time to fix them.
Even if you can't weight-bear through the injured foot for a while, you can do any exercises that can be done sitting down or lying on the floor. Core stuff and flexbility work generally doesn't need feet! I even did one-legged planks and push-ups.