Visited in February of 2019 the week before Carnival. Great time to visit as there were hardly any tourists and only a few other travelers. Downside is a lot of the restaurants aren't open and some tours are shut down. Upside is you get to live like a local in a insanely touristy town 10 months of the year. We were able to grab a very nice 1 bedroom apartment in the old town center with a kitchen for 150 euros for 5 nights (30 euros/n). Probably 10-15 restaurants were open in the old town, including the main grocery store. It appeared most everything was getting ready to open for Carnival, which probably marks the end of the lowest season (Few days after New Year's to Carnival). We did all the touristy stuff, and saw no other International travelers but a few random couples and one Chinese tour bus that overnighted (Right as COVID was taking hold...) We walked the walls and saw less than 20 people in 2 hours. If you want to avoid the crowds you can't beat Dubrovnik in the winter.