Spend the first two nights in Strasbourg and the next two in Colmar, leaving after the fourth night on day five. The short regional train between them makes room for two different city stays: Strasbourg’s pink-sandstone cathedral, canal-side working quarter and imperial avenues, then Colmar’s market streets and the paintings at Unterlinden. Day four combines the museum with a short train outing to Turckheim, a wine town whose surviving gates give the afternoon a clear walking route. You can keep that afternoon in Colmar if art matters more. May, June and September suit this combination of town walks, outdoor meals and indoor collections; April and October also work with cooler evenings. The plan uses one hotel change and central railway stations. It offers a specific small-town visit without requiring a rental car or trying to cover the whole Alsace Wine Route.