With temps to about -25f actual possible here I setup to keep them out of the wind, so no grip concerns other than the evening jostling for position
If I were using dowels I would go at least closet pole diameter, probably V-notch a 2x4 mount that to the wall and then run a screw down into the...
Seems to me they do OK on the ground and they don't get to curl their toes around that. Then again I am looking at this from a colder climate perspective and here dowels would freeze toes.