Need a good insulated tub for keeping fish fresh on long desert drives

So I do a lot of camping and off-road trips around Liwa and sometimes up towards Fujairah, and the one thing that always annoys me is keeping food and drinks properly cold when its 45 degrees outside. My old cooler barely lasts half a day before everything turns into soup. A friend told me I should look into getting a proper insulated storage container instead of those cheap ones from the hypermarket, but honestly I have no idea where to start. I saw some options on a UAE site while searching around and the insulated tubs section looked interesting but I wanted to hear from people who actually use them before spending money. My main question is whether the thicker walled ones really make a noticeable difference over a full weekend trip, and if the sizes they list are practical for a family of four or just for solo trips. Also curious if anyone has tried filling them with ice blocks versus regular cubed ice, and how long each actually holds up in direct sun. Not looking for anything fancy, just something that wont let me down when Im out in the middle of nowhere with hungry kids complaining.