Yep, fresh install as your OS is probably getting further down the supported list so you may as well keep ahead… Once downloaded and installed, perform a full OMD backup of the old instance, copy to new host, restore to new host. I performed this recently both as a fresh install / migration and also P2V from an old physical host to a new VM. I was missing some RRD data but for me most importantly all my hosts, services and rules were all in place, even nagvis was still working!
Good luck!