There is more to the airport than just the CCR, so ignore those who tell you two or three hours is enough!
It’s your first visit and if I were you I’d make the most of it. Go early, have something to eat and drink as appropriate. Go to look at the shops and buy a Hermes tie and a bottle of some aftershave. Visit the J and F lounges and compare the wines on offer (you don’t have to drink a whole glass but risk a sharp eyed FTer noting someone taking a sip from a dozen wines and leaving a nearly full glass, hence starting a long thread about behaviour). Take time to explore the T5 tunnels and visit the B terminal J lounge to decide if the popular view of it is right.
Go back to the CCR, shower and eat again, drinking full glasses this time. Lounge around for some time before reluctantly trudging off to your gate to enjoy your flight.
You’ll have a great day!
PS. If you’ve not been on them throw in a trip on the PODs to the car park and back; it’s free and fun.