TransAlpina is an amazing part of Romania with incredible views. I must admit I wouldn't be driving in there during winter though ;0) I crossed it two times years back and loved the experience. The only place similar to this that I found was the PanAmerican Highway in Ecuador where I found myself counting a third level of clouds!
Wow, that must be great! I've never been there but I can only imagine :D
Oh, but as I said the road is closed during winter times. So you can drive again in any of the other seasons :)