Our very first timeshare trade trip was 3 timeshare weeks in Spain in 1998, and it was totally fabulous. It went from fabulous, to more fabulous, to most fabulous. It's what got me hooked on timesharing, after we'd first bought a cheap resale, then traded 2 years worth of weeks thru RCI and got a third bonus week. I think you and we like to do similar things. There was a deal thru Iberia Airlines called "See Spain" which included flights to anywhere in Spain including islands -- but with low-cost carriers it could be replicated. Itinerary was:
1. Fly to Malaga, rent a car. First night at Alhambra, then 7 nights at a beautiful timeshare in Estepona. From there we saw Ronda, Casares, Mijas, some other white towns, Tafira, Roman ruins along Atlantic coast on the way to see ancient Cadiz, day trip to Tangiers thru timeshare (yes we thought it was worth it), a dressage show in Malaga, afternoon in Nerja and Balcony of Europe, I'm sure there was more.
2. Drive up coast, overnite in beautiful white town Mojacar at what was previously a timeshare and also rented by the night. Then drove to Alicante, flew to Mallorca. Timeshare in gorgeous Cala Pi, where we got the exact same picture-perfect view as was featured in the RCI dream book, couldn't believe it. This island is outstanding for varied landscapes, scenic coves, terraced mountains, ancient history, Roman times, Moroccan architecture and gardens, Chopin
etc.
3. Flew to the stunning Canary Island of Lanzarote, I don't recall whether we flew back to mainland and then there, or ferried back and then flew. This was the biggest surprise of the trip because I knew so little about it and it was beyond amazing to me, largely because of brilliant architect Cesar Manrique + the topography of the little island. From there we also overnighted on Fuerteventura (ferried over and back with car). I could go on and on, but I dream of a return trip. We did visit 2 other Canary islands on subsequent trips.
Our second trip to Spain was gonna be 3+ weeks and didn't occor, ever: it was to have happened spring of 2020, tightly planned, but everything shut down for covid just as we were supposed to leave. It included 2 timeshare weeks and a bunch of private reservations in Menorca, overnite(!) in Monserrat, Costa Brava, up briefly into French Riviera, then over into Cathar territory, and back down thru Pyrenees for hiking and cave art to our multi-night stay near Sagrada Familia in Barcelona. I have no idea whether I'll re-create it, maybe.
Of course you have a zillion options. We spent a month in Portugal after which I dreamt of moving to, and did quite a bit of research on, but I think we got too old ... and southern Italy to see at least Pompeii which was mind-blowing and Sorrento.
Good luck!!