I saw on another forum, some more videos on the new Sienna (from Canada). Looks great. Still no discussion or info on the clearance though. If it's based on the highlander platform, maybe it'll be a bit higher than the current Sienna model.
Seriously getting excited about this minivan. I was considering the 2020 Highlander but the third row seems almost useless to me. Yes I took it for a test drive. It's a nice vehicle but others SUVs do a better job of managing space. Going to wait for the new Sienna.