One good thing to come out of this thread: it reminded me to defrost my freezer – now.
Right now, in Ontario, we have a January cold snap: daytime ~ -10, overnight ~ -20. This is the time to defrost. Just put the freezer contents into a plastic hamper and put it outside the back door while you turn off the freezer.
(The only problem is what to do with all the melt-water from an upright freezer. It either ends up all over the basement floor or I use a bucket brigade of old towels shoved in the freezer compartment alternating with putting said towels in the tumble-dryer ).