Beth Otway, better known as "Pumpkin Beth" produces a useful list of Galanthus events each year, which is always shared in the forum - this calendar from Beth encompasses all sorts of specialist plant fairs, plant sales & seed swaps:
https://www.pumpkinbeth.com/2020/01/2020-specialist-plant-fairs/No idea how she manages to get all this info together- must take hours of work! Very useful it is , too!