VENO 2 Pack Insulated Reusable Grocery Bag, Food Delivery Bag, Durable, Heavy Duty, Large Size, Stands Upright, Collapsible, Sturdy Zipper, Reusable and Sustainable (BLACK, 2) https://www.amazon.com/dp/B07DS29MY4/ref=cm_sw_r_apan_i_TP5ZSEK1J9HQBZ1Q1WVA?_encoding=UTF8&psc=1
I use these ones. 2 for $16 on Amazon. They are very sturdy and larger than most insulated bags. They cannot fit those huge restaurant bags or large pizzas though.
https://www.amazon.com/gp/aw/d/B07DS29MY4?psc=1&ref=ppx_pop_mob_b_asin_title
I put two of them side-by-side in a collapsible bin in the trunk I already had. They also perfectly fit the $4 cup caddy from Michael's.
https://www.michaels.com/12-pack-assorted-6-cup-caddy-with-handle-by-creatology/MP554271.html
This works out perfectly because you can store milkshakes and stuff in there without any spillage.
I have 3 of them now because I lost one and ordered 2 more. Sometimes, I still run low on room in larger stacks, but they're rarely not enough.
I may eventually get a large catering bag and a large pizza bag.
VENO 2 Pack Insulated Reusable... https://www.amazon.com/dp/B07DS29MY4?ref=ppx_pop_mob_ap_share