We stayed at Snow to Sun in Weslaco when we had dental work done in Nuevo Progreso (note only one S) a couple of years ago. It's out in the middle of farms, but convenient to the border. It's a snowbird kind of place with activities and most people seem to know each other. We didn't hang out there at all.
We chose it because it was Passport America and therefore cheap (we already had the PA membership). I just checked their website and March and April are still high season--$33/day. PA is valid starting in April, and it's $16/day with a six-night maximum. Regular price drops to $20 in May, in case your trip is delayed.
