if a bunny gradually gets used to colder weather, minus degrees isn’t a problem. As long as there’s shelter against rain, snow and wind and you serve warmed water twice a day (or better yet, get a chicken water heater) because frozen water can’t be drunk (of course). The rabbit should be elevated off the ground and have a hidey-section with straw or other bedding material in it.
You can’t put an indoors bunny outside in very cold weather, the temp difference shouldn’t be more than 10 degrees C (sth like 18 degrees F), because a bunny needs time to grow thick protective fur. They also need some extra food if the live outside in cold cklimates. You can give extra pellets or supplement with whole or rolled oats.
Bunnies should also live near other bunnies if they live outside. It doesn’t have to be in the same cage/hutch, but they should be able to hear and smell and if possible also see each other. Bunnies don’t like loneliness.