How is LXD tied to openstack? You can use LXD in exactly the same way you used LXC (with a nicer CLI interface, no less).

nova-lxd adds lxd as a "hypervisor" choice for openstack, but it's a completely optional way to use it.

Try it on ubuntu right now: sudo apt-get install lxd; lxc list (yes, the client for lxd is called lxc, it's kind of confusing. Sorry.)

Disclaimer: I work for Canonical, but not on LXD (I use it daily outside of openstack though)