My sewer pipes are about 6 feet down and normally they'd be fine. Combine extreme cold with partially blocked pipe (roots) and it's a recipe for disaster. The father/son sewer service were great though and, they're also car guys so, it's all good. I haven't been snowmobiling for almost 25 years. It was fun but got too expensive and we kept getting less and less snow here(some winters the trails never even opened in this county) which means you had to trailer up north, get a hotel room, eat out, $$$$$$$$$$$$$. Besides, I can't stand the cold as much anymore. Getting old(er) really sucks IMO.