Just as a side note, the 2+1 rule for shotguns is there because of the migratory bird act, the limit is due to the way the regulations are in place for migratory birds in Canada/Ontario.
Have at it with the 22, I like to put as many in the magazine as will fit so that I can bury the other ammo in a pocket that will not get filled up with snow.
Rabbits with a 22 can be a good challenge, I rarely did it, we just just jumped them and used a shottie.