Pretty much identical situation: married to an otherwise great guy who doesn't happen to enjoy travel as much as I do. I do have kids who are now teenagers, and they've actually been great travel companions.

I've done all of the options listed here: enlisted a local friend (one great experience, one dreadful), met up with people I already knew at my destination, met up with people I'd met online (via travel and food forums) at my destination, etc. I've formed very close friendships over the years, with all sorts of people from all over the world.

I've never signed up for a course at my destination, but have done something similar that you might like to consider: booked a "cure" at a spa. Typically these last a week, and you're busy being pummeled and sprayed and wrapped for half of the day (alternating mornings and afternoons) and then have the rest of the day and the evening to do whatever you'd like. Spa + hotel + food (demi pension or pension complet) are usually a good deal, and the hotel typically arranges outing to local sites and even some evening entertainment. There are inevitably other solo women there and I end up going out for dinner, etc. with one or more of them. The environment fosters a certain degree of camaraderie. I've done this twice, both in France, but there are similar options in lots of places.

Another option is to go on evening guided walks, as I don't particularly enjoy eating alone, especially at dinner. So an evening walk can either take the place of dinner, or in some instances actually include dinner, or maybe just drinks and snacks if it's a pub crawl sort of tour.