I always try and flesh them while they are green, much easier, I have salted them after they dry just roll up and put in a dry place, works fine, but freezer is not a problem for me, I have 2 just for such stuff so now I just fold them flesh to flesh and freeze until I am ready to work on them. If you get them fleshed very clean to start with, not much chance of spoiling, they just turn into hair on rawhide in a few days.
I have about 25 or 30 in the freezer now, better get to work.
Pappy