hee, hee, hee.... prepare for craziness!!!
on the assumption that you are all in one big room.... divide & conquer. set up beds for your kids so they are not next to each other; one either side of the bed if you can (or whatever configuration you come up with). bring nightlights.
since your kids have very different bedtimes, have 1 parent put your ds to sleep in the normal way. the other parent should take dd out somewhere. perhaps there is a game room in the hotel, or they can just go for a walk & go by the pool, or the playground, or the lobby. wherever.
once your ds is good & asleep (and you have nightlights on), then dd can return & you can get her ready for bed when it's time. she is old enough to understand being quiet
keep your windows covered. it will help.