Jizera Mountain was something new for me, odd mountains. Probably Wysoki Kamień is one of the most visited mountains in that range (there is a nice looking private shelter there, I was too early there, so it was closed).
In Szklarskarska Poręba I entered (Karkonosze)[https://en.wikipedia.org/wiki/Krkono%C5%A1e].
The only difficulty is to reach Szernica, then it is easy.
I was sleeping in a tent that night near Odrodzenie shelter. I remember that night as one of the coldest.