I posted this on regular forum but thought there might be a little more experince on the subject over here. :

We currently draw water from the lake with a jet pump for our Canada cabin. Ditching the jet pump for submersible next spring. Plan on keeping cabin water seasonal but want to be able to have water in new building for when we go up in winter.

Old neighbor had in line heat cable that could freeze in the line without being damaged then thaw line in half hour or so after they would get there and plug it in. They did this several times a year. The “Heat line” brand is crazy expensive, but they say its ok to freeze. I know the neighbor didn’t have that brand years ago.

If anyone uses an in line heat cable that’s able to freeze/thaw without damage I’d appreciate knowing the brand. Need aprox 250’

I would use the stuff for gutters and roof eaves. Run it in the pipe you are using for water supply.
My concern would be water lines bursting when full of water and freezing.
I am assuming the heat cord you are asking about is for the supply line from lake to building. Why not just drain it before leaving?
Just Google Gutter Heat Cable, and you will find what you need.