I visited Tallinn Old Town (Vanalinn) in November and absolutely loved it. The Christmas Market in the old town square had just opened but it was not super crowded. I worked from my AirBnB for 2 weeks and Internet was always on point. The entire city was very walkable there were cafes and pubs and restaurants just a few doors down (I was near St Olaf's Church), to no more than 10 minutes away by foot. Uber and others were no more than 2 or 3 minute wait. Definitely go check out the memorial to Estonia's victims of communism or the former KGB prison cells. Very sobering.