Aw, I only wish I had the same problem as cold weather. Where I live, this time of year in the Northern hemisphere, it's almost 80 degrees outside. Inside the room with my grow box it's a bit warmer, and that always spells trouble with my 150w HPS. I don't even want to mention the humidity [ ugh.. mold ]. Maybe it'd be best you started now, anyway? I mean, once that warmer weather starts coming around, the plants, being a bit more mature then, will benefit from it perhaps? I wish you and your plants the best, and hope they all sprout for you.