I think something like that is possible starting from the already generated ssam data, let me think about it.
Regarding the ssam graph for 1 year, that was actually my use case!, you can see a 1 year graph on the repo readme, it took my laptop about 5 minutes to make that graph.
I have generated graphs for much larger periods of time ... BUT, if your datasource is a Winston server then please be cautious, I don't think Winston can handle that kind of loads. Unless you have a very good wave server (FDSN or SeedLink), don't try this on a production machine, instead, you can set up a separate FDSN dataselect server such as this one
and use it to generate graphs as large as you want.