I'm late to this discussion (too much work at work over the last few days, and too little time at home to read and keep up), but I would have asked about the seating arrangements, specifically what kind of seat is on the bike that is going to be used for the long haul.
As others have suggested, the factory seat on the S40 (and the Savage before it) is pretty weak in terms of padding and comfort.
I put a Corbin on my Savage and like it, though I would note that even with that I feel uncomfortable at times and I'm never going all that far (typically 30 miles or less per trip). It beats the stock seat by miles, but still isn't a magic bullet.
I have a gel pad that I could put on the bike if I wanted (I bought it when I had the original seat on the bike), but I tend to just use that pad under my butt when I'm surfing the web (like now). That pad is really too big for the bike seat and overhangs the seat on the bike. On the other hand it does make my office chair more comfortable
I hadn't thought too much about the roughly 100 miles between fill-ups, but that does sound about right. Going much further would certainly push the fuel situation more than I'd care to try for, but that said I've actually been running on reserves more frequently than I should be (a couple of round trips to/from work from home pretty much drains the tank and leaves only the reserves. With so much work lately I've not been as good with the OCD on filling the tank as I should so I've gotten to run on the reserve a couple of times in the last few weeks
)