Yup, I remembered to open the vents with the velcro piece. In fact, we had the window by our head entirely open, and we cracked the side windows too. Even then we had quite a bit of icy condensation, but it was 18 degrees and we were in the tent for 11+ hours. I think the solution to the problem is to get a nice heated shop.
All joking aside, I do miss being able to drape my dewy rainfly, tent, and tarp over the banisters and let them air out in the house. It looks like the rainfly of my Simpson III is removable, but I'd rather not deal with the hassle of removing it and reinstalling it later. Besides, the rainfly isn't the only part of the tent with condensation on it, so I'll have to wait for warmer weather to dry it out anyway. Not a deal-breaker, but I thought it was worth mentioning in this thread.
I don't mean to sound like a complainer, we're really enjoying the RTT. It's fun, it feels like I'm a kid in a treehouse.
The pad is a tiny bit firm, but I like that I can't feel anything poking through it, and it seems to keep us pretty warm. We've been throwing a blanket between our sleeping bag and the pad since the nylon can get a bit chilly, and that has helped quite a bit. I'm looking forward to trying it out in warmer wather, though I imagine I'll still run into the same issue when it gets drenched from rain.