If you plan to be away from the game, save your Subscription time!
This is, in fact, a good thing. Freezing an account sounds weird and usually is a result of a punishment. However, during my regular Regular SWTOR SubReddit scout, I have discovered a thread where user Dragoon- has shared his experience contacting CS via a phone call with a request his active Sub to be frozen while he is unable to play the game.
In short, you can call Bioware Customer Support and ask them to freeze your active account and subscription. They’d do that with no questions asked. Once you are ready to return to the game, you can call them again and they will unfreeze your account granting you back your remaining Subscription time.
I cannot say for sure, but logic dictates, that you cannot even log in to SWTOR in the mean time. It’s is not possible to save your Sub Time for later, but keep playing the game as Preferred.
As usual, my thanks to the very informative community on Reddit (despite the few down-voters who seem to never ever like anything :P).
Well, speeking of Subscriptions, did you subscribe to my newsletter and email notifications for new posts? You can do that from the top right corner of the main menu or from the page footer. Thanks.