Just working out my timings for cooking Christmas dinner. I've also just watched a Gordon Ramsay thing in which he said you should rest the turkey for as long as you cook it! (He was cooking a whole turkey though, not sure same would apply to just the crown) I'm sure I've only ever rested it for 15-20mins before.
Watching because I need to cook a turkey crown tomoorow as well
Jamie oliver covers his whole turkey in foil and tea towels for up to 90 minutes. I'm giving it as long as it takes to the roast potatoes (I'm also doing a Quorn Roast but it's fairly obliging provided it's not overcooked )