I have several esky's that I use for different occasions.

If I just want a few drinks at a party I take this
coolar-25-l-blue.jpg

If I need a lot of drinks and food for a party or picnic I take this
coolar-55-l-blue_1_1.jpg

On long 4wd trips I have taken an insulated esky similar to this (not evacool, cannot remember the brand I have).
With the last Simpson trip I did we took it as a overflow for the fridge and filled it with frozen cryovaced meat and dry ice and did not open it for 5 days. When we did open it all the meat was still frozen.
0000697_fibreglass-icebox-60-litre_1100.jpeg