I do it every trip now, friend showed this to me.

...very small styrofoam container (holds about 1-2 pops...like a extemely small minnow holder for ice fishing)...catch your sunset walleyes...throw them on a chemical cold pack....they're raring to go down the gullet in the AM.  No more having to get up early and fish.  You sleep late knowing you got fresh ones ready to go.