I didn't have much trouble by just booting from an Ubuntu 16.04 USB stick and installing it to the entire SSD on MBP 2015. Almost all of hardware works, but require installation of some modules and changing configs.

Shameless plug: I prepared an Ansible playbook that does those manipulations automatically: https://gist.github.com/a-rodin/7930a50befbc7b07e20c5c3b5aca...