Unfortunately you will find fireworks pretty much everywhere. It's a tradition in most of Europe on NYE.
Some of my worst fireworks experiences happened in isolated spots 'auf dem Land' where we went away hoping to find someplace less than a war zone. Problem is, there are very few truly isolated spots in Switzerland.
In less crowded places you will still find people setting off private fireworks, but often with less consideration. People will travel to these places specifically to set of larger fireworks that they are not supposed to use in crowded neighborhoods. And in isolated areas, the time restrictions are less likey to be adhered to.
I have learned to stay away from any hotel, Gasthaus, or tourist area, as people are there to party and enjoy the holiday.
Not to mention, if you opt for a hotel, guests will complain if your dog barks in fear. Also, be aware that some may charge an extra fees for pets on that night.
Added to that, should an emergency occur, in isolated areas you might be far away from veterinary help. If you are somewhere where you don't know the local vets chances of finding emergency help can be limited.
I spent many years with an epileptic dog, which meant many years at the Tierspital on NYE and 1 Aug. Then there was the year a neighbor deliberately shot fireworks directly at the dogs taking a much needed piddle break, injuring one..
Another reason why we don't go away is the small but still non-zero chance of a dog bolting in fright and getting lost. In its own neighborhood a dog at least has a chance of staying safe because he knows the area. In a place he does not know a runaway dog is even more vulnerable.
In all my years here, I have learned that the safest place is actually my own home. It's the place where my dogs feel most comfortable, so we are starting out from a better frame of mind.
I close all windows, pull down shutters, close off rooms on the exterior of the house, and keep to either the cellar or an interior room. I keep music or a film playing.
Most important is how I react. I keep calm, but I don't ignore the dogs. I calmly, quietly acknowledge that they are upset and give them low level comfort. TTouch, massage, etc. In recent years the old idea of 'ignore your dog's fear so that you don't reinforce it' has been debunked by most respected behaviorists.
Here is a good thread, running over many years, where EF dog owners discuss how we cope. You can see over time how our strategies, and advice, have evolved. Hopefully you will find ideas that might help:
https://www.englishforum.ch/pet-corn...all-noise.html
Good luck!
Oh, and if you do decide to get away, book early.
ETA:
There is still time to do effective desensitization work ahead of NYE. Do you have a trainer here? If so, ask for help with that. If you don't have someone to work with here and are interested in more on the subject, let us know and I'll post some links.