There might be better ways to do this but each new instance on vultr takes a few minutes to set up (you can actually use their web VNC console to watch their install script run，a unique experience not offered by other VPS providers I have used) and then you can restore old config from a snapshot which takes a bit more time but it is pretty fast overall.

There are options to load your own distro image and init scripts but I have not tried them since most things I need in a transient instance can be installed by following a simple bash script calling apt.