I planned on stashing micro spikes near the tonto trail junction somewhere. At least I would have them for the return. Not reaching north rim because of ice is a bummer, but if i get delayed coming back and have to negotiate the ice, cold, dark and exhaustion without micro spikes. Seems dicey.
I don't know, if snow is fairly certain at both rims I'll just carry. My poorly planned cold weather clothing is probably a better place to try and save weight. Well that and the fat ass IMAX camera man I now have to carry.

