I wouldn't make too big a deal out of it. Go on vacation. Have fun. If you feel like doing active stuff, do it. Go hiking, diving, rock climbing, cycling, wake boarding stand up paddling or whatever is going on where you're going. But do it for fun, not exercise. If you want to lay around the pool and get your exercise getting to and from the swim up bar and the buffet and/or reeling in some fish, do it. It's 8 days. It's a vacation. I wouldn't do push ups and pull ups and what not. Either way, I would try to do some light mobility stuff each day to stay loose, get a massage or 2 etc. I find I stiffen up a little if I totally lay around for any length of time.
As far as transitioning back in goes, I wouldn't expect to lose much in that period of time. You might even be stronger. Listen to your body, see how it goes.
Don't overthink this thing.