peter wrote:
In the unfortunate event of losing electric power for days during freezing
weather, what is the best way to prevent water pipes from freezing?


The best way ... basically same as a cottage, drain the system (switch
off that now empty electric water heater), put antifreeze in the
toilet(s). FWIW, my water tanks are in the basement and have drains on
the bottom ... can't imagine a tank that doesn't have some means of
draining ... e.g. for replacement. A short length of garden hose to the
floor drain and I can drain the system ... which I've done to install
new copper lines in the basement.