Good luck. I started the Best Friends household (Becca Clarke and Julia Wright) for testing purposes. I didn't have any problem returning to Wyvern Hall from Darby's Den. I didn't test water balloons because it's winter in their game right now.
You might try going to Willow Creek for your holiday if you do end up reloading an earlier save. Most of the neighborhoods in Willow Creek have barbecues and I think they all get water balloon buckets during the summer.
Thank you for your response. I did the game repair, and all is well. Found my main Sim sitting quietly in the TV room inside Wyvern Hall. I was able to have the others join him. Yay! Not sure what the issue was, but the repair fixed it. So very happy. Starting over wasn't truly an option for me at this point.
