Well the bubbleglazing is working a treat, especially in the bathroom. It is noticeably warmer in there first thing in the morning, I'd say by a few degrees - and that is the only thing we've changed. The bedroom is also staying much warmer, which we suspect has as much to do with plugging the small gap as the bubblewrap. Then again, given the bathroom results I'm sure that the bubblewrap is helping, even though it isn't on all the windows. You can really feel the difference just by comparing the feel of the window vs the feel of the bubbleglazed window
In fact the other morning Jerry and I work up and said to ourselves that it was almost too warm, the difference is so apparent!
In answer to your question Nelly we used double sided tape to stick the bubblewrap, but Jerry's found a few sites like this one that say you just spray water on the window and stick, so we're going to try that with the other windows we're planning to do. Will let you know how that goes.