What does your Polar Package include? SOME have electric heated holding tanks and can EASILY handle temperatures down into the teens as long as they're plugged in to 120 volt power. If your tank heaters depend on furnace heat then turn the furnace to it's lowest setting (just to be safe) and it should be just fine. Either bypass and empty the water heater or leave it turned on also.
Chances are that it would not receive any damage down into the upper 20s even if you do nothing but I'd always prefer to err on the side of caution.
Good luck / Skip