Bald Paul Last fall after my summer cancel due to not needing it, I found that Zwift was giving a set amount of time free monthly before requiring renewal payment. Also as you noticed if you drop and come back you jump in exactly where you were as far as game level, history, follows and followers, and drops. If you use the Companion app you can even keep in contact with those you follow and continue to give ride-ons and comment on their activities.
For me it will really depend on the weather we have. Mine renews on 5-11, probably go another month then cancel. We still are having a number of windy days and it is nice to have options.