We have a grey/silver igloo or coleman that we use for the once or twice day opening and keeps stuff frozen for several days. For the regular opening I have a 'normal' cooler that gets ice replenished. The milk jug full of ice is also a great idea and keeps your cooler dry which bag ice does not. I also use a smaller 12 can cooler for beer which I put bag ice in and the water helps keep it cold.
Also, I just bought these ice packs for my lunch bag. I put two in and they are both mostly frozen at the end of the day. Just a normal lunch bag and stuff is kept very cold. There is something in the packs and you just add water. Would definitely consider these for camping:
https://www.amazon.ca/TOURIT-Reusabl..._ba_s_1_t&th=1