I cancelled it months ago, because I projected being poorer and trying to tighten my belt. Then I thought better of it, and so I wanted to resubscribe.
Although my subscription was good through August 12, the system would not allow me to reactivate it early, would not allow me to update payment methods, although it was tantalizingly displaying several "upgrade" buttons for more expensive plans. And it was also displaying a prominent yellow banner that told me I had cancelled "but I can restart it anytime!"
So in mid-July, I contacted a support agent. And they started explaining to me that there was no way to resubscribe until the day it lapsed. And I described their banner and they said welp, just wait for that day. And they also repeatedly said "you can contact us anytime and resubscribe!" and I kept telling them to quit lying!
I was also reminded of a terrible threat, that email is counted in disk quota, and if I was in excess of 15GiB when the 100GiB subscription lapsed, my email would be disabled! Since I can't guarantee I'll have the subscription for life, I'll just have to ensure I never exceed 15GiB, even though I pay for 100, sad...
So the termination day rolled around, and I contacted support to ask them why I couldn't restart it, and they said I had to wait for the cancellation email (different story than the first time around) and I was finally able to safely renew, and hopefully set up autopay on that too.
The funny thing is that if the One subscription lapses, I'd of course lose access to those live agents as well, so if I had any further trouble, I'd be screaming into the void. I mean, if One expires, you're over quota, email won't work, you don't receive the email, you can never resubscribe, nobody will help you... ouch.