Non-incandescent freezer light bulb

Fluorescent will not work well that cold. Efficiency is not a big deal here as it is only on a few hours a year. If you save a penny a year that is not going to pay for a more expensive bulb.

Do you have short life on other bulbs? If you tend to have a higher voltage, they will not last as long and that may be your problem. Don't buy a cheap "no name" brand either for the same reason. A good appliance bulb should last quite a few years in a freezer. Here is one rated to last 4000 hours

Buy a name brand bulb stated for refrigerators, is your socket loose and moves. Forget any other type, your bulb will last for maybe 10 years if its not hit or vibrating and is a proper bulb

Such short life means that the lamp is burning more hours than you think or it is being subjected to shock or vibration which causes the filament to disintegrate as soon as it crystalizes (100-200 hours or so). Is there a chance that the lamp is staying on when the door is closed due to a faulty switch? Do those who use the freezer typically slam the door or is the socket loose?

If you have none of the above problems, buy a "long-life" or 130 volt standard lamp. Lamps marked as "applicance lamps" may actually be rated for relatively short life so they can deliver higher light output. If you have shock/vibration problems, try a lamp designed for garage door openers. Such lamps have additional filament supports that hold the filament tighter.

All of the lamps I've described are typically stocked by the big box retailers or a good hardware store.

TKM

I bet one of those Edison base led exit lamps would work pretty damn well but might not be moisture proof without a slathering of clear silicone sealant.