Fiberglass pushed hard to compact is loosing its R value.
You want good insulation, get polyurethane sheets, who come in different thickness at HD. Their R value is about 3 times the fiberglass.
Coolers are hard to judge.
We have 1 which we bought over 30 years ago. Very convenient with storage in the top for plates and utensils, but it looks old-fashion comparing to today's coolers. Still I was carrying frozen steaks in it, while having it in the cab and after 12hr trip the steaks were still frozen.
Newer coolers are nothing close.
When compressors by its own offer better efficiency, than absorption, there is much more to make efficient refrigerator.
I did test 2 years ago and my absorption fridge can come down to 0F (at night) in 100F temperatures (at day), so I am not looking for replacement.
