With not having vents it can cause condensation and if you live in Canada like myself you can get a problem with snow melting off the roof and causing ice. It's the air space that helps prevent that, as in normal sized houses your attic space is roughly the same temp as outside give or take.
That's not to take away from the amazing job you have done, and that shouldn't cause to much problems, as you don't have a foundation to divert water away from. It would be the condensation in the ceiling I would keep an eye out for in winter time .