I’ve just fallen down that rabbit home in expectation of the legalization here in Germany. It you want I’ll send you my notes.
The short of it: growing outdoors might be really difficult in Germany, as you have to make sure the plot isn’t visible to passers-by or your neighbors and their kids. At least that was how it was phrased before the new revision today.
That being said, there are a number of strains that grow outdoors in Scandinavia. Professional Seed retailers like royal queen seeds have dedicated info pages and/or filters for that usually.
Googling “grow cannabis outdoor cold climate” should set you off in the right direction.