Hey folks,
Just managed to change datadir in nextcloud snap and I wanted to quickly share it for the posterity.
just install nextcloud with snap e.g. from 29/stable
sudo snap install nextcloud --channel=29/stable
then
sudo nextcloud.occ maintenance:install --data-dir <YOUR PATH> --admin-user <YOUR USERNAME>
then update the trusted domains
/var/snap/nextcloud/44391/nextcloud/config/config.php
depending on your setup and finally
sudo nextcloud.occ maintenance:mode --off
You should be good to go then 