With no fridge =think about the cost of ice every 1.5 days????
maybe two eskys 1 with a small block of dry ice covered in something,to stop burning,to keep thigs frozen,the othr on withsome block ice & some normal party ice.
Ithink that would keep 4 a bit longer.
To make your own block ice ,get acouple of plastic ice cream containers,fill them 6/8th full & freeze them.
this a just a thought .
hope it hope it helps