Wait a month or so on repotting - it will benefit it more if you do so as the season starts to get warmer. Posting a picture would help, but lopping a limb off would tell you if it's still alive. I've had a number of plants sulk for years and finally grow, and I'd think yours is hardy (in terms of putting up with changing conditions).

Here is a link to a few photos: http://flic.kr/s/aHsjy6GuxF

If I lop of a limb, will it just be dry and brown if dead? And if it is alive, can I propagate it?

Here is a link that might be useful: QON photos

Hi there, neither of the links above will allow me to look at your pics as it says we need to log into the account using your own password!! Or maybe it's just me?
Gill from the UK.

It looks like it for sure needs new potting medium. I don't think moss is good for most succulents, especially cacti. I can only assume there is potting soil underneath the moss. When you do re-pot it would probably appreciate something more porous. There are more knowledgeable people on here than me on this matter so I will let them suggest a medium and guide you further.

~Erin~

In your photos it still looks green and plenty alive to me. I'd suggest that you just give it some fertilizer once it warms up again, and with more light and a little push from feeding, it looks plenty large enough to give you a good amount of blooms this summer.

New soil does wonders especially well draining soil plus a little fertilizer would give it a nice shot in the arm, it sure wont hurt anything, you have nothing to lose.

Greg

New soil is always nice for a fresh start and adding a little fertilizer will also be a nice shot in the arm.

Greg

One shouldn't fertilize until it's in active growth. I agree that you can repot it (and wait a few days before you give it a sip of water), but now is not the time to fertilize it. You don't want a lot of growth in the winter on this plant, as it usually will come out spindly (because of lower light levels).