anyone know?

Many variables,

We catch spec trout in La, ice them as we catch them,
leave them on ice till filleted , bagged and returned immeidately
to fresh ice, draining water adding more fish and ice each day. I have left them like this for 4 days, but prefer to leave them no more than 2.

MO

If their gills turn white they are bad.

I usually just ice them over night and then fillet them the next day, so far so good.

24 hrs max for me.

The longest I've kept them is overnight, and like mentioned above if the gills are pale and not bright red or the eye is clouded over I would not keep them.

24 hours max, and keep the water drained off. IF I need to keep them longer, I gut and gill them then ice them down and put a layer of rock salt on top of the ice. This lowers the temp of the ice and will actually lightly freeze them. Again keep the water drained off.

I misread the OP, The whole trout thing was based on
cleaning them right away, icing them for transport back to
Texas.

Back in the day , We would fish western OK in float tubes
all weekend , fish would go in ice alive and all be cleaned
on Sunday evening when we got back to Texas. No telling how
many possesion and transport laws We broke back then.

So 48 hours on ice before cleaning is the most I've done.

MO

Overnight is about the longest i would push it.

Around 24 hours is what we use as a max time. But a slurry of saltwater and ice. Seem to work well.

-bump-

As long as the gills are pink to red you are ok. If they are white then they are no good. Thats the old rule that i learned when i was young and it hasnt failed me yet. I have kept fish on ice for two days or so.