Arghh this sounds fantastic! I've often thought about doing something similar, though I'd want to improve my skills more first. I'm not sure I'd build a log cabin. It seems like it would be a lot of work, though it would be amazing to have one finished; I'd probably go more semi-mobile, something like the shelters the Evenk use in Siberia if you've seen the RM series. Some room and fairly comfortable, yet you could pack up the walls and take them with you say in a canoe, and see a bit more of the country too. Might also prevent too much damage being done to one particular area.
Then like you say use the land to provide food but take some basics to supplement that where necessary.
Really does sound like you're going to have a great time. Unfortunately I'm not going to be able to take much time off until mid next year now
I'd have bitten your hand off otherwise!
Just a thought - if you are interested in a blog or something like that it might be worth getting in touch with a few of the national papers, see what their thoughts are. They might be interested in running some kind of series almost in real-time, or otherwise I'm sure you'd get LOADS of people reading anything you put online. With a satphone / PDA and small solar panel or water / wind generator to recharge the batteries it wouldn't be too difficult and, assuming you wanted it, the same kit would also act as a useful connection to home.
Good luck with the trip anyway - I'm well jealous! :You_Rock_