Welcome toots!! We're up here in MN also! Yes, it got cold a few days in January but it's thawing out now. Today was nice and this weekend it should get up to the 30's F. We're out of the DEEP FREEZE now
Here is a good thread on HHO and freezing:
hho generator and freezingAnyway... In MN, it only got to -20F for a few days this year in January. You can read the above link and try some of the recommendations to keep your HHO from freezing and simply un-hook the generator and bubbler on the predicted cold days and put it inside if you don't want it to freeze.
EddieRock