The best bag I ever used came from
Walmart.
In April we went to WDW and stayed in a condo.
When we left, we had food I couldn't bear to throw out.
I went to Walmart and bought an insulated bag in the sporting goods area where they have coolers.
Can't think of the name of it right now, but it's silver and kind of quilted.
When we left our condo, I filled a couple of ziploc bags with ice from the ice maker in our fridge.
We went to the parks for about five hours, then drove to Tampa to fly back to Ohio.
When we went thru security at TPA, the ice was still frozen!!!
I didn't have to throw it out because it was still within their guidelines of being solid.
We made it home after a five hour flight and an hour and a half drive home, and my food was still totally cold, and the ice was still mostly frozen!!!
I was amazed!!!
The bag is only about $15, and it is best thing I have ever used!!!