The learning curve to Linux is a bigger step than described. We tried at the Radio Station and found there just weren't suitable apps in more than one instance. Those that might have served were another big learning curve. If you have bespoke software like VBA macros, it is a non-starter. I tried looking at Libre Office (on Winodows even), supposedly compatible, but trust me, there were functions I couldn't replicate, and even tried work-a-rounds and gave up. My software works, I write it to simplify life (and improve accuracy) and even then it has had subtle quirks. Throw in a different environ and you may not know where to go to solve the problem, even if you can spot it immediately.

The bestest system in the whole wide world is the one you have invested years of experience in. Only can we have it 10 times faster?
If you, or a friend, can negotiate the tribulations of installing an SSD - I say go for it first. (they can come with easy migration apps so look for that option). And all your working files are available on the old HDD as internal or external disk, in file structures you know!