I split Rescue between 2 locations, though it wasn't exactly a referral - did the EFR/class/pool stuff at home then the OW on a trip with the same shop though not the same person. I wouldn't have wanted to do the whole thing on vacation, but for just the OW part it was fine. You might contact places you'd consider doing it and ask them how it would work with them.
While there's arguments for taking classes at home in cold water and poor viz where it's more challenging, especially if you plan to dive there, I don't see anything wrong with doing it on vacation if you're sticking to warm water diving - especially if you won't do it otherwise. You could argue it makes sense if that's where you dive. (By the time we got around to Rescue we had long since bagged cold water diving.) It doesn't necessarily mean you get off easy - where we did it the water may have been warm, but the instructor managed to find a place with worse viz than home like 1ft, and do other things to up the challenge. Everyplace has it's different challenges, and some of the stuff we did might have been easier in heavy wetsuits, And of course plenty about the class is not just about the diving anyway.