You don’t have a shut off where the water line comes through the floor? Maybe things are different up here but every fixture has a shut off.
There are several reasons why they’re put deep. One like you said freezing water, there are times even insulation doesn’t do the trick. Another and probably the main reason is liability. If a shut off fails and destroys your house you’re going to be even more ticked. It’s easier to replace a small section of a yard than someone’s entire life (house). Another reason is it makes it pretty difficult to turn water back on after it’s been shut off for non payment when it’s 4’+ underground.
I Doubt this’ll help ease your frustration at all, but I tried. While you have the water shut off, install some shut offs on your fixtures to prevent aggravation in the future.