At least it didn't happen with 200lbs of fish in the back.
We routinely travel 200-350miles with 2-300lbs on ice in a cooler, the meat is always just fine. Done both gutted/headed or filleted. If I can't get them in the freezer in about 3 days, Id package and freeze solid with dry ice. I wouldn't drive 5 days with fish on ice. I've seen salmon go south in 5 days. Also if its filleted, it will go bad faster. Ocean fish can go south even faster because most are not well cared for by the crew/deck hands.
I'd watch the deck hand when they are filleting them. Most are really shitty at keeping the meat clean, but are super fast at getting it off the bone. I've told the last one to stop and I'd deal with it when I got home. I didn't want nasty meat. It was awful, guts, bile, ink you name it all over the fillets. Those get fishy super fast even frozen. I've been on probably 30 ocean charters, and I can count on 2 fingers the crew that took care of the meat. The rest just slice and dice and toss it in a bag for you.
Not sure what you're fishing for, but if you can keep them in the round, on ice, you might make it 5 days, but its still pushing it IMO.
Hope you can still make it.