James "Cubby" Culbertson wrote:

What type of heater are you thinking of?

Whatever works the best! My girlfriend's father suggested propane, but
I have visions of an unattended propane heater blowing up my cottage.
Is this a realistic concern?

An electric one faces the same
issues
as using heat tape (ie. lose power, things cool off).

I was thinking of electric, hoping that the larger area wouldn't cool
off fast enough for the pipes to freeze if the power went out for a few
hours. My intitial post was sort of seeking input on whether there is
a heater (preferably with a thermostat) that I could safely leave on
when I'm not there.

I've done this.
I installed a drain at the lowest point of my system. When I leave, I turn
off
the main, open the drain, and fill all my sinks/toilet/drains with RV
antifreeze.
I have heat tape/insulation on all the lines under the cabin for when we are
up there
but I haven't had an issue yet. The added benefit to just shutting the
water off
is you eliminate the potential for a burst line or leak (I've got a
washer/dryer) when I'm not there.

The cottage was built so that the water can be drained, but there is a
hot water heater and (excuse the clueless term) large tank with water
and air that is part of the pumping system. I would hate to have to
drain and refill everything every week or two. OTOH, maybe there's no
realistic alternative.

Thanks, cc.

Gideon