Is it safe to transport meat in a coolbox with ice? If you buy say sausage rolls and pork pies on a Thursday and keep in the fridge overnight, then travel Friday for 5-6 hours with them in a cool box with ice blocks, then put them back in the fridge Friday overnight, then serve up for buffet on the Saturday, is this too many temperature changes over 2 days?
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.