I posted this in the past when someone else asked about storage in hot temps. You may find it helpful ...
I live in Texas so I understand the challenges of temperature extremes in the Southwest. As I like to take road trips with my wife, I was particularly concerned with leaving the batteries in the car, when stopping over somewhere for a meal, etc as temperatures can go up high real fast in a closed car. So when I purchased my
Mavic 2 Zoom, I also got a mini-fridge like the one below. It can be powered by 110VAC, USB, or 12v lighter adapter, all options that are included in the package. I remove the shelf inside and it has room to store 3-batteries + remote controller + 10,000ah power bank. Very handy!
I use the 12v lighter adapter when we are driving, which keeps the temperature in the fridge down to around 60F - 70F (measured with an infrared gun) . When I shut the car off, the fridge also shuts off as my outlet needs to have the car running for it to generate the 12v output. But if you leave the fridge door closed, it stays cool and safe for the batteries for quite some time even with the car off.
Incidentally, in order to save money, I also keep our house at 78-80F during the summer. So I actually keep the batteries in the fridge even when in the house. In this case I run the fridge using USB as it will not get quite as cold inside as when operating it on 110VAC. Again, while in the house, I find that they fridge stays at a nice 60F - 65F inside.
To make sure there is no condensation on the batteries or remote controller while in the cooler, you can (and should) store them in a sealed plastic bag. I use the fireproof LiPo battery bags (link below) for the batteries, and put some moisture absorbing gel packs in each bag to pick up any extra moisture that may occur. So far, I have not had problems with moisture or bulging .. knock on wood.
Here are some Amazon links (no affiliates) of the fridge, LiPo bags and Gel Packs that I use:
Cooluli Classic Black 4 Liter Compact Cooler Warmer Mini Fridge with AC/DC/USB Power - Great for Bedroom, Office, Car, Dorm - Portable Makeup Skincare Fridge
Anbee Mavic 2 Lipo Battery Safe Bag Fireproof Storage Bag for DJI Mavic 2 Zoom/Pro Drone (Small, 3-Pack)
Dry & Dry 3 Gram [50 Packs] Food Safe Silica Gel Orange Indicating(Orange to Dark Green) Mixed Silica Gel Packs Desiccant - Food Safe Silica Packets for Moisture Absorber Silica Gel Packets