Love Blizzard Beach and River Country both. Never been to Typhoon Lagoon. Since River Country apparently isn’t going to open back up which of the 2 parks would be best for our larger group of 12. We would probably want to hoard 4 or 5 lounge chairs as a home base, 3 of us (Mom and 2 daughters) would hang at the chairs with drinks maybe watching younger kids play in kids area while thrillsters would experience the park with 3 Dad’s. All kids are excellent swimmers.
Here is a link with photos of the River Country opened in 1976 and after it was abandoned in 2001. I think it has just been demolished to make way for “Reflections” I would have loved to explore it. https://www.themeparktourist.com/features/20150323/30074/abandoned-rise-fall-and-decay-disney-s-river-country