You can cancel any time, and your subscription will run its full course (you've already paid for it). Then re-subscribe with your preferred plan when it expires. If you wait to cancel until the day it's due to expire, you could overshoot it and it could renew before you get the chance to cancel. So anyway -- and I hope this makes sense, I haven't had my morning coffee yet -- if you're going to cancel and re-subscribe, cancel now, enjoy your GA until it's due to expire anyway, and then sign up again with an upgraded plan. :)

We realize it's not ideal, but it's how we have to do it at the moment.

Yes, I can shed some light on this. I started implementing it in January, finished several iterations of it, and have been working through some unexpected considerations we ran into along the way.

The original plan was to release this in late February. However, it was delayed - along with everything else on my todo list - for reasons explained in my site update post here.

(If you aren't part of the siteupdate ping group, I highly recommend joining so you don't miss out! There is a link in my signature below. You can also check admin post highlights periodically for the most important updates.)