I envision taking my family (it is at least ten years away) through Canada, across Alaska, under the Bering Strait through a 65 mile-long tunnel, across Russia, through Ukraine, then Poland and Slovakia. Then, on to Prague in the Czech Republic, through Germany on the autobahn and into France. Leaving France, we'll drive through the now second longest tunnel, The Chunnel, and into London.
I think two months for the drive there and one month for the drive back will do.