Richard Holub wrote:

The SKIPPY filter is made out of a RUBBERMAID water trough which is very
rigid and should withstand the freeze. It is used outdoors for watering
farm animals.

It _should_ but I would bet it isn't guaranteed. My dogs have water buckets
made (it seems) of the same material. They haven't split yet (in quite a
few years) but ice has definitely made them bulge in places they didn't
used to :-)

Congrats on the frog. I understand researchers have discovered that they
can actually generate a kind of glycol to keep the cells from rupturing in
sub-freezing temperatures. It must have been quite the surprise to see it
wake up!
--
derek