Is it safe to transport meat in a coolbox with ice?
As long as you have enough ice to keep them cold the whole time, that's the same as just putting them in your fridge for a couple days: they'll be chilled, stay chilled, then get served, whether warmed or just naturally brought toward room temperature.

So be sure you have enough ice, and as usual be sure not to let them sit out forever to serve, and you'll be fine.