Caroline, if you have an extra styrofoam box or cooler that you could put your seedling pots into, you could use this alternative for the 2-3 week fridge temp: if your outside night temps are ranging, say, -10 to 0°C, put the closed cooler in the garage for 4 days, then 1 day inside the house, then 4 days in the garage, then 1 day inside the house, etc. If you have an extra thermometer to put inside the cooler, it would be interesting to check the temps through the duration, but it is not rocket science. You only need to be in the ballpark of diminishing temperatures to reach your aim.
