Not recommending any particular chain or resort, as we all have different preferences. Just wanted to share specifics on wintering at AI resorts as a few folks requested. We spent 6 wks this year at a beachfront AI in Cozumel, Mexico end of Jan to beg of March (before we escaped to Portugal to ride out covid) for an average of $1,077/week for 2 adults all-in, which translates to about $4,300/mo. No flights included. Resort is Barcelo's Allegro Cozumel. It is not fancy, but the beach is beautiful, several pools, nice grounds & dive shop on site (extra, not incl in my figures). We loved the winter temps & lack of humidity (unlike summer). We booked 1 week at a time, as you can cancel like at a hotel in case we needed to cut it short for any reason, but you have free cancel option ONLY if you book directly with Barcelo. So we had six 1-week bookings ahead of time & just paid each week as we went (prices varied a bit each week Jan/Feb/March).
If you join mybarcelo on their booking website (free, just like joining Hilton or Hyatt hotel loyalty program) you can get a small discount, plus 5% discount for seniors (over 50, I think), plus often stackable 5% promo code if you search for one online. Also free wifi for mybarcelo bookings. They charge for wifi otherwise.(!) We are not timeshare owners & simply refuse to attend any presentation for such & they do not bother us again. It is a terrible "investment". Timeshare owners we met said they had to pay $40pp for AI part (unllmited food/bev) with no option to opt out, plus the annual "maintenance" fee which sounded to be ~$600/yr for 1 week, plus whatever buy-in payment they were talked into. We paid an average of $153/day all-in. Do the math, but I said nothing to the timeshare owners we met unless they asked what we paid. Just fyi, Barcelo has plenty of other properties you can see on their site. They have a price calendar for all (just don't enter dates) & they frequently have sales, at least precovid, lol.
This is just our experience with Barcelo & I suspect very similar options, sales & booking direct to save $ for lots of other large AI resort chains. BTW, we found that we got treated like gold by staff staying so long, lol. We had our choice of the days & times for the (free) premium restaurants the following week before the weekly turnovers every Saturday/Sunday. I am sure that is the same at any AI, as they are so used to all new ppl every week. We plan to do it again when we get to place where we need a long & carefree break after some intense nomadic travel, but that might take awhile, cause we are all on a LONG travel break right now!