I fully agree with John, that with just a day or two, it really would be very sensible to focus on one village, or at least a pair of nearby villages.
I’d also suggest going ‘off-piste’ as well (i.e. not just the greatest names), as sometimes the experience at a smaller ‘under the radar’ producer can be truly special, more so than at the established elite. From a Spartan tasting room at Accomasso (but with the most rewarding insight, with my Italian struggling to cope), to feeling like a family friend at Mirù, there are some memorable experiences to be had.
I like that you’re talking about 1-2 wineries in day, as whilst it’s feasible to squeeze up to 5 in, that really is making it a route march.
The question is what to do with the remaining time. The castles are interesting enough and a good long and slow lunch is very rewarding in the region. However I’ll put in a strong recommendation for walking. The vineyards are almost all open to walk freely through (hurrah for fragmented ownership), and it makes the wine taste all the sweeter when you’ve stood on (or climbed up) its slopes. Just walking past signs saying Cerequio, Moccagata, Brunate, etc. etc. raises a smile. There are some decent slopes, but it’s never that far to the top, and you can always take a break by going around the hill for a bit before heading back up. There is an excellent walking map for about €8 in the tourist info shops, and it’s worth it, but not essential if you keep landmarks such as La Morra, Castiglione Falletto etc. in mind/sight.
The excellent tourist office www.langheroero.it now have a booking service for wineries (no charge, except if you don’t show up). Some of the prestige places aren’t listed, but their list is pretty huge. The also have extensive listing details including saying which have an English speaker at the winery. I tend to email direct (in Italian) but many will be fine with English.
Driving? Will you have a car/designated driver. Assuming yes, it may still be sensible to stay within walking distance of the wineries and a restaurant. In that way you can all taste freely and have something nice to drink at lunch and in the evening. I use google maps a lot these days to ensure the logistics are as easy as possible, and always try to plan wineries where you can walk from one to the next. The fresh air alone is a good reason, but it takes so much pressure off the designated driver.
I hope you enjoy the region, it really does have a lot of charm and although Barolo itself (and to a lesser extent Barbaresco and La Morra) is starting to get quite touristy, it’s still got plenty of its soul left.
regards
Ian