Not having power does slow you down but you get through it and appreciate what you do have. Power lineman from many states gave up their Christmastime with family and everyone in Maine does appreciate it!
We had an unheated rabbitry for many years and know the challenges of keeping the bunnies safe and in good health. Here are a few tips:
Pre-storm preparation - Fill up water jugs for the bunnies if you rely on an electric water pump. Make sure you have plenty of hay and grain. Don't wait until you are close to running out as bad roads may keep you from re-supplying.
Hay - During very cold weather, consider putting in nestboxes for all your bunnies, even the bucks. Stuff in hay and give them a chance to be comfortably warm. They will get into the boxes when they choose. If they simply have a hutch compartment stuff that with straw and hay to insulate it.
Water - Providing fresh, not frozen, water can be a challenge but absolutely necessary to keep rabbits eating. A rabbit will stop eating if there is no water to drink or if it freezes before they are ready to drink. Not only will they lose condition and become thin from eating less but they will also dehydrate. Our rabbits drank greedily each morning and evening. We watered all of them first and then put in the food. That way they paid attention to the water first. We didn't use water bottles, we used dishes. Back then we used metal dog dishes and would pour hot water on the back of the bowls and pop out the ice into a pail. (plastic bowls crack) If you use the plastic dog dishes with the molded indent on the bottom, you may pour hot water in that rim and let it sit for a few minutes until the ice releases. It's tempting to "pop" the back of a plastic bowl before it is ready and that is what leads to weakening/cracking them. If it happens, don't throw them out, use them for food instead.
Some folks have two sets of water dishes or water bottles and will "trade" them off in the a.m. and p.m. They just load the frozen ones into a bucket and lug back into the house to thaw. The thought of using water bottles though scares me that their little tongues will stick to the tube. (Double Dog Dare)
Grain - You should "up" their grain portion (hay too) as they will burn more calories to keep warm. They'd probably appreciate the carbs in a slice of bread as a treat too.
Oldsters - Some of the very old bunnies may not do so well in the cold. Consider making them house bunnies for the winter. Take care when you do that they don't become overheated if they've been out most of the winter. Also remember that you can't simply put them back outdoors until probably March when temps are reasonable. Days may seem sunny and bright but nights can still be bitter.
Daily care - If you usually feed and water a.m. and p.m., consider if logically possible to check mid-day with water.
Wind - Make sure there are no drafts or breezes on the bunnies. Drape or attach grain bags around cages. Granted, this was easier when grain bags were cloth and not the wax-y paper they are now. Put plastic on the windows and open areas.
Acclimation - Don't bring bunnies back and forth from a cold rabbitry to a warm house, they need to be acclimated to one place or the other for the duration of a weather change. The thicker coats they start growing in the fall help get them through the winter. No different than you putting on a warmer coat. Same thing with going to shows. Don't bring them into a heated building all day and then put them out in a cold rabbitry at night. Sure, it is a pain lugging the carriers back and forth but a small price to pay to keep them healthy and comfortable.
Supplies - Don't forget to bring in any supplies that may freeze like tattoo ink, wormers, fly sprays etc.
Heating - Use caution with heaters. Keep hay, rabbit fur and other flammables away. Check on the heaters. Hopefully it is plugged into a circuit breaker type electrical outlet. If you use heat lamps, make sure they are clean of hay and fur also. And that no wires are within reach of the rabbits to chew on.
Any other ideas, please share and I will post for others to read.