Well is over 1000 feet down a hill, waterline is buried in some places, exposed on top of ledge with dirt around it in other places, temps drop, water freezes, no water. We pump it to the tanks every couple weeks when it is warmer and then purge the line back to the well. Water stays under the house, so it won't freeze and we have indoor plumbing!
Complication will be more valves and filters, but it will be a simple swap of a valve and transfer switch (yes a generator transfer switch) to actually swap from one to the other. During the winter there will be a dump valve that still has to be opened, at least that is my plan for the time being, I may try and figure out how to make some sort of bypass system, currently you either have to remove the check valve in the fall or you have to pull the pump off the pitless adapter to drain the main line, I want to try and make it more automatic if I can, who knows, I might not be able to update anything without making things worse.....