Navigator, after watching a couple of my peers die without warning, a couple of others faced with your sort of situation, and the general tendency of people to become less able as time goes by, I'd opt for the lump sum and go do the traveling you so desire to do Now. You know you have a short window of opportunity, a lot of us are dealing with it as a 'what if'. It would be slam-dunk to me.
I don't know what aspect of 'proffing' you like most, but when I did it, the most enjoyable part was the classroom teaching. If that's your sweet spot at work, part-time adjuncting (as opposed to the recently villified full-time version) is very rewarding with none of the office/academic politics. I spent a year as dept chair, and I had a stable of reliable folk who did specific classes, and some were retired and using the teaching gig to support the travel habit.
Thanks for your observations, ggbutcher. One of the great things about being a professor is that one has a lot of options. It is possible to teach in an emeritus position or as an adjunct. It may also be possible to keep teaching and take summers/ winter break/spring break off and travel. I usually worked through these periods, but that doesn't seem so important now.