Solar panels don’t perform well when covered with snow, but the temperature isn’t an issue. The main issues are length of day, and angle of the sun. There are calculators that can estimate solar production based on your latitude.

Solar panels create some heat as they operate, and get less efficient as they get hotter. This can theoretically pose issues in hot climates (I’ve never had problems in Australia at 40°C/100°F), so freezing temperatures is actually beneficial.