Yeah, I saw youtuber Clare Siobhan take her Eco fams to Granite Falls to have a wedding there and ran into the same problem. She had to download a mod to make it residential I think. Im not real sure of the mods name but if you are able to download them just google "vacation worlds as residential" or something like that. She still had a time doing it, maybe watch her video to get some ideas? ?♀️ Fingers crossed you get it figured out. ?
Edit: wow, Im such a nitwit, just saw your last statement about not doing mods, so now I feel terrible. I wonder if you could use the enablefreebuilds cheat and change it to residential. But I think that still wont work as vacation destination worlds don't come up in the options for your venue. Maybe you could decorate a lot to look like the vacation house you wanted to use with some debug items around the edge to disguise the background not being Selvadorado(?).
