RC51,
I am a bit deeper south than you are but last year my 1-7/8 acre pond froze over for 4-5 days during the cold spell we had but I kept my diffusers running 24/7...I have 3 stations of two-9" diffusers at each station, depth 6', 8', and around 9' without any visable affects on my LMB/CNBG/NBG/RE/CC/HSB/Cypres Trout or Rainbow Trout.
I'm not sure how this relates to your area but thought I would offer what I have seen here.
Data, Data, Data......
