To really test the bag out, I climbed in in damp clothes every night and used it to dry them out, hence the bag getting damp in the bivvy.
It never felt cold though, presumably becuase the moisture had moved through the insulation and got stuck in the outer layer..
On the 7th day, it rained very heavily and water was dripping on me all night from the tarps ridgeline, and also from the sides (never had this before, the condensation was ridiculous. The tarp had gone slack due to the deadmen melting out and the nylon slackening). I was outside of the bivvy bag just lying on the downmat and the top of the bag was soaking wet. It didn't soak through at all. I used it the next night without drying it out knowing it wasn't going to drop below -5c , again to test it and it was bone dry the next morning. It certainly seems to stay drier than other synth bags I've owned, even those with monofil batting.
Lots of lessons were learnt, very valuable ones too mate. I had no place being out there before without this training, I would have been a liability.
The skills need practising though, and a return is being planned for next Feb;either Canada or back to Scandinavia.
I can't wait for next winter again now!