Sorry to hear about the folks. FWIW, it's more common then what many would think that aren't snowbirds yet. Part of the reason I like the road so much. It's hard to see good people/neighbors age that are older then you. Hearing stories of how one spouse forgets how to brush their teeth adding that to the list of things the other spouse has to do is heartbreaking.
Harlingen airport is a great little airport to fly in and out of. For some odd reason hotels seem to be expensive in Harlingen. Lot of hotels on SPI that would be at a discounted rate that month and the weather should be nice. Would be a 45 minute drive though to Harlingen.
