We have a Canyon insulated fish bag, quite large guess 60 x 30 inch, used it for more than 6 seasons.
Throw in 4-6 gallon frozen seawater milk jugs into it. After fish is bled put them in. Have been able to keep 2 man limits of hali and salmon etc ice cold for a weekend. Just add new frozen jugs or chipped sea ice.
Has a drain plug to let out the thawed water and a breeze to clean. Hose or power wash. Very sturdy zippers and carry handles.