I was going to chime in, having done a series of UK countryside rides in the mid seventies through mid eighties. Not exactly tweedy, nor with three speeds, but wandering and more locale-orientated than "I'm going there tomorrow" sort of thing. I did many of these as a member of Youth Hostels International - Youth hostels actually accept people of all ages, or at least used to do... and they are usually no more than 50 miles apart... they allow you to specialize in what is in the immediate environs, and almost always have a 1:25000 scale OS map on the wall, and often literature to plan your perambulations. I did this in Denmark too... they have unisex rooms and Tuborg Gron there...
I know my 60 year old knees would not appreciate second gear on a three speed. There's some hills in many of the nice parts. Wobblyoldgeezer seems to have had a nice time, but hotels and B'NBs can become expensive.
I hope you get to realize your dream, choteau. Happy trails!