Bunnies handle cold very well if they have shelter from wind, rain and snow + appropriate bedding-material. They should have a hidey-space that’s elevated off of the ground if the floor is cold or if there’s a cold draft, and they need a little bit extra food to keep warm. If it freezes, you need to serve them warmed water twice a day (because water freezes).
Rabbits as a rule do much less good in hot temperatures. They principally disperse heat via their ears since they don’t breathe through their mouths and they don’t sweat. At colder temps their ears tend to get cold, that means they are saving heat by not sending warm blood out into the ears. If their appetite is good and they are normally alert and active, cold ears don’t mean they are too cold.
You can give a little bit of rolled oats extra if it creeps down to temps around 32 F. And remember the warmed water if it gets that cold.