I also plan to travel no more than 200 miles a week and some weeks I may just stay put if I find a nice spot. That is related to costs of course but also to pace of life and my plan to deliberately keep the travel less stressful than has been true in other forms of travel in the past.
I like my own company fairly well and I expect that very few of my own hobbies and activities need to be left behind. I also expect to have time to develop new interests and pastimes as well, as the adventure progresses.
I like to 'tour', regardless of how I may travel and whether I travel alone of with a partner or friend. I expect those expenses would vary little whether traveling alone or as a couple because most involve individual admissions. Like GM above, I would not spend money just to stay busy.... That is easy enough to accomplish in other ways...

So much is free for the taking, if we only choose to avail ourselves of it. Also, let's face it...none of us are really roughing it in our units generally and if we get bored, we can resort to computer or TV or whatever. For that matter, if we are really bored, we can just move on!
I must admit that I have already booked two caravans in 2009, both to places I have desperately wanted to visit for years. The tours like these for me are less about the traveling companions (but who knows how important those may become?) and more about the organizers putting together cost-effective packages I could not hope to replicate on my own.
I don't care how you look at it, one is always cheaper than two. Also, keep in mind that people I met traveling last month who had been full-timing for several years even said the travel was cheaper than they had initially feared (and that was couples) and many were already using other ways to compensate for rising fuel costs, like more creative exploration of potential boon-docking sites...
The world could be your 'oyster', ecarbone. What else has you freaked?
IM