For the OP:
I have never worked with a well, but have buried boiler lines, and water feed lines below ground between buildings. I second all of the suggestions about burying it as deep as you can. We are the same latitude as the Southern part of WI, and have had some bitterly cold winters. Frost has gotten over 5' deep. For decades people have been putting frost walls at 42"-48", which I feel is a serious mistake. They end up heaving and cracking. We just buried some boiler lines, and did them at 6'. Frost is the major reason people around here generally build with full basement walls.
I'm a big fan of Wirsbo PEX. (Uponor) It can expand quite a bit if it freezes, and goes back to shape after defrosting. The expansion rings can take the abuse, which is not the case with most (if any) crimped connections. You can buy pre-insulated PEX bundles that might be something to consider.
If it were my off grid house, I'd first locate and drill a well. Pour a foundation around it with ICF forms down at least 6', maybe 7'. Then build a small shed around it to house well equipment, and possibly a generator, solar panels, etc. Build a hatch on the roof that seals well, but could be removed if you ever need to yank the pump out of the well. Better yet, do all of this at the edge of what-ever foundation you might have for the house/cabin.
Wellbuilt: for frost protected footings, the general consensus is to put 2" or greater foam out a couple of feet from the foundation, horizontally. Extra layers do help. For your well line, I'd center minimum 2' wide insulation over the line, but wider would be better. Check out some of the places that recycle foam, and pick up a bunker of it.