40+ and retirement in the Caribean, I think that is called having it made. Anyway, these people were in their 20s around the mid-00 mark. Conscious interest in music starting somewhere round their teens, i.e. mid-80-s.? Clearly the + part of the audience will go even further back.
There will be some testing the waters with some very mellow versions of very big hits in the house/deep house arena if you are feeling adventurous and want see their reaction. But if you prepare for a mainly house/deep house set, I would think you are moving on a very slippery slope.
These people were young in the 00s and before. While house/deep house was around, it was only one musical style that was popular not necessarily THE popular style. And without certain knowledge that is was, I personally would have a very strong backup plan b, containing stuff from the 80s through the 00s in various styles/genre, including mainstream hits from the charts, and if this mainly an American audience, be sure to include some rock songs as it wasn’t all “dance”-like music that was liked well in that time frame. Rock had quite a following too. And I might even take care I have some late 70s stuff with me if the age spread is wider than 5-10 years (i.e. 50+ people there also).
Clearly all my two cents worth, but that is probably because I am going at this as a mobile gig where the audience make-up determines the genres to be played. Gigs like this are all about preparation (what to bring) and execution (crowd-reading and knowing what must come next).
My comments where mainly aimed at preparation. You are on your own with execution as you can only figure that out during the gig.
Hope that is of some help.