To put a finer point on the issue, they were 2 40-50 foot long tapes. (it's been a few years since I put them in)  and the tank is probably bigger than 130 gallons. 

I'm not sure who would be using an "unscrupulous contractor" as we dug our own water lines from the well to the corral and I know that line is 3 1/2 feet deep. (can't imagine paying a "contractor" of any sort to do something I'm perfectly capable of doing myself)

What I can say is we've had -30 degree weather here in past and never had the stock tank or supply lines freeze up. (I suppose if someone were real industrus they could build a small well insulated shed just outside the corral run in electricity, get an old water tank set at the lowest possible setting, and "warm up" the water before sending it the rest of the way to the watering tank)

Was below zero this morning when I got up, hight point of the day was 10 degrees and at 4:30 it was already 4 degrees F again and starting to snow again. 1-1 1/2 foot snow on the level, drifts,, up to 3+ feet. Pretty much our winter time conditions.

For us when the cows are carrying snow around on their backs that's good, if there's no snow on their backs they're struggling. Can't imagine anyone with cows having calves in this weather here. 

Thing to remember is that is HERE, my location and conditions.