Follow up on LA servers: although my VPS had been moved to LA, my databases were still in Virginia. It just took an extra day for them to move the databases over. That was just completed last night.
Now that databases and VPS are both in LA, sites are all back to quick loading. RAM usage has stayed under 300 with no sudden spikes.
From the original posters comments about his RAM going back up, it sounds like location (in this instance) is not a factor in how a site is performing or RAM usage