Different versions of ubuntu with chroot environment

I was trying to setup a chroot environment on older system using debootstrap. I had ubuntu 14.04 and I was wondering what version of ubuntu i can possibly install on it. If I were to try and run ubuntu 20.04 should there be any risk for the host system? And more generally, how far apart can the versions be - is there any limit at all? While the problem was solved by simply upgrading the old system (about time) the question remains. When I tried to set it up i used debootstrap to create chroot folder in something like

/root/${distro}-root

, then I mounted folders as in [here](https://wiki.debian.org/Debootstrap) . I then run chroot on that folder. Everything worked as intended. After that though when I rebooted the host system it would not boot up.