Battery pack for back up power to a wine fridge.

I have a large Vinothéque cabinet that holds 440 bottles. It’s noisy enough that I keep it in the garage. I’m in Southern California so heat and blackouts are a definite possibility. How much power should I count on as a reserve and does anyone have a recommendation for a battery pack? I got one from Costco and the information on the box is letting me know that 900W was a serious underestimate. I wrapped the fridge with fire blankets for a bit of extra precaution but I’m sure it’s pretty minimal.