Ironically enough, I have an ADR for the 4pm show next Tuesday (May 26th). Crazy sauce! This will be my second time going there solo. It was a blast! The show had me laughing throughout and the little crowd interactions were fun too. You definitely have to "go with the show" and be just the slightest bit outgoing and you will have a great time with it for sure. Although I remember looking over at this other table with an older couple there, they didn't "interact" or even crack a smile much; I suppose the food alone makes it worth going for . But I think everyone should try and experience it at least once, it is classic Disney. I was there the week of its 40th anniversary last year; apparently its been worth it for this long, I say give it a shot!
And if you want some dinner company, I would offer to pull up a chair for ya. Not sure if/how that works (I always travel solo), but let me know.
I am trying to hold an unofficial mini-meet up for Wishes on the 22nd. I (and probably a few others) am looking to hang out in FP West for the fireworks if your HDDR plans fall through.