Winter use outdoor freezer

Last winter, I kept a cooler outside to use as a freezer. This worked well for several months, but I was wondering if anyone had any ideas to extend the use of our freezer as daytime temperatures rise. In late February/March, the temps still dip below freezing at night, but the daytime temps can get up to 50-60.

I'm somewhat interested in building a more permanent freezer that I could potentially use year round, but right now, I'm most interested in something simple to take advantage this upcoming cold season.

If you could bury, or partially bury your cooler in the soil it would insulate the cooler somewhat from the warmer temperatures.
If you were to put some type of insulation over top of the cooler then this would help even more.
That is what I did when I was camping.

I have exposed a cooler to the cold night sky and then closed it up early in the morning. This works in areas that experience a large diurnal range. Raccoons will steal frozen food. A balcony or roof is safer.

I've used the same cooler as a bread box water heater. Plastic milk jugs full of water are illuminated from all sides of the brilliant white interior. A pane of glass seals the heat in. Close the lid and you can have a solar bath at midnight.

Leave a drain open and add fresh snow inside every night. No direct sun!