You don’t mention using it so that’s why I think, the first thing I would do is adding a CDN this would reduce a lot of weight from the VPS as the bigger requests would not touch the server.
Adding to the CDN, I would also go with S3-like storage that would allow you to scale differently the storage and the VPS resources (if your community is uploads heavy).
This recommendations help a lot to reduce load and the price increase is a lot lower than a bigger VPS.