Old Town weekend, island summer or a month in Tallinn
Three days in Tallinn's Old Town, with Kadriorg and the Telliskivi creative quarter, fit in the 3 GB pack, which lasts 15 days. A week that adds Lahemaa National Park, the university town of Tartu and the beach at Pärnu is a 5 GB trip, most of it maps, bus tickets and photos.
A summer fortnight on Saaremaa and Hiiumaa, with a car and the family's tablets on your hotspot, is a 10 GB stay. A month working remotely from Tallinn is the 20 GB pack, and like the 5 and 10 GB ones it runs for 30 days. If you are torn between two sizes, take the larger one here: tickets, parking and payments go through apps, so running out halfway costs more than the step up.