Unless you want to brumate to provide yourself a 'break' from caring for your animals, it is not at all necessary to brumate your corns for breeding purposes.
I'm in southern Ontario and haven't brumated for years. I keep my corns in a room that faces north with access to natural sunlight through a window. They get their cues from the natural light and cycle themselves. I don't mess around with temperatures, I keep feeding as usual, and everything works out fine. 
My females generally ovulate from late January to mid February each year.
This season I have had a couple of females who ovulated in early January. A few weeks earlier than they usually do. If I had to guess, I'd chalk the difference up to the milder than usual winter so far.
As many have stated over the years, brumation is my no means a requirement for breeding corns. Heck, I have some males and females who have NEVER been brumated and still bred just fine for 5 plus years.
Good Luck!
BB

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"Have you hugged your drummer today?" --- Me