And here is the hoop-house that I built for it the first year. Although I did manage the overwinter the pond successfully without the hoop house last year I do plan on re-using it this year and into the future. It is a bit more work to set up and take down every year but has quite a few advantages. One of the most important being the ability to feed the fish for longer. It effectively lengthens their feed/growing season (spring-fall) and shortens their dormant season (winter).
As I mentioned before, with the hoop house the ice rarely froze at all, it gets quite warm under there when the sun comes out and that's one great thing about Calgary. Even if it is minus 30 degrees outside the sun could be out in full force. If you google it you'll see lots of people using these hoop houses for their ponds and/or gardens.