I'm a long-time Linode customer as well, and over the years I've been scaling my services up but the pricing model is quite restrictive! I also need more disk space, but not necessarily RAM and CPU...

For what it's worth Linode has said (in Feb, 2017) that they will be announcing block storage in the coming months.

https://blog.linode.com/2017/02/14/high-memory-instances-and...