Moving to a new VPN (Virtual Private Network) was as simple as signing up for a second Linode instance, and then building it to my specs. Eliminating half the cruft I had on my old system saved about 40GB of space. Now I have room for all new cruft.
I decided to stay with Drupal for this site. Frankly, I just don't want to muck with content systems anymore. I have a couple of new sites on Wordpress, this on Drupal, and that gives me a foot in two worlds. I was reading that the Drupal 8 upgrade should be button-press easy, especially if you haven't customized your site. Sure sounds simpler than fighting to get it into Wordpress.
Linode's new billing system made the move a whole lot easier, and cheaper. I was only charged for the double VPN until I dropped the original once the move was finished. I think I'll take this approach the next time there's a major Ubuntu upgrade. Not only can I cleanly upgrade, this approach gives me a chance to clean my system.