Hi Paul,
I undertook a similar trip myself not so long ago. I went to see my GP beforehand to explain, and he upped the amount of insulin on my prescription, i.e, so instead of one box, I had three each time I requested it. I just kept putting the prescription in, so eventually I ended up with more than enough insulin to cover my time away - which was around about nine months. I also invested in a 'friobag' to keep the insulin cool.
For god's sake, don't let being Type 1 cause you to reconsider an adventure of a lifetime! Plan and you should be fine. Perhaps make a visit to your GP and ask for advice? Maybe get a letter drafted in the language of any foreign speaking countries you might happen to stumble across, explaining you have diabetes and what insulin you take, etc. I have heard you can get such letters drafted - unsure as to where though.
Hope this helps...