The longest tour I've ever done was Rowan's and my very recent RTW tour, and that was 8 months ... although, in a way, it's still sort of tapering off.
Prior to that, I have also done a 3 month tour.
In both cases, I ended my employment, packed everything into storage, and set off.
(And I've done a lot of other travelling and moving and living in non-traditional conditions (like living for a year completely off the grid in a shack in the hills) and doing non-traditional things (like returning to Uni full-time in my late 30s))
As for your questions:
1) Yes, we do think about the future. And we make plans for it. One of the things that both Rowan and I have done is to continually acquire further education and experience in a variety of areas.
2) No, I don't get bored on tour. I get bored if I stay in one place too long, and especially if I'm not out exploring the area around that place.
3) Because our extended tours aren't more than a year, and have gaps of a few years between them, there's a good mix of home activities and touring.
4) Regarding the nice, warm, dry home ... it wasn't those features that we missed because you can find "nice", "warm" and "dry" in hostels, hotels, B&Bs and all sorts of places ... what we missed, from time to time, was having a place of our own, where we could make our own decisions. And when I felt "homesick" it wasn't for a particular house, or particular location ... it was for my sofa.
