Okay, this was too easy 
Here is a little how-to for those who want to do the same:
- Clone old drive to new (bigger) drive using Clonezilla etc.
- Install and run Gparted (you can also do it manually via Terminal). You might be prompted to fix the GPT when you run Gparted, so click “Fix”.
- Now change the size of the volume that holds the encrypted volumes, mine was
/dev/sda3, by right-clicking on the entry in the list and choosing the resize option. Commit the changes with the green check mark. - Now close Gparted and start Terminal
- In Terminal enlarge the
/dev/fedora/rootand/dev/fedora/homevolumes to your liking by running the following command:lvextend -r -L+100G /dev/fedora/rootandlvextend -r -L+100G /dev/fedora/home. I chose to keep the 50/50 split that I had on my old drive and added the newly available space on the drive in equal parts to the two volumes, but you can change the100Gto fit your needs (the+symbolizes relative values not absolute sizes). I’m not sure if the-roption is strictly necessary, but I found it in theman-page and thought it might be useful - After the command is done and the volumes are resized, you can verify your changes by running
df -h.