I went back to the "Switch to the cloud" page this morning and tried upgrading again. I signed in and pressed the blue "Buy it now" button. This time, I got the expected payment page for upgrade.
I was excited to reach this page and upgraded my membership. But to be led around in circles last night just wasn't right. Would it have killed someone to put up some kind of "closed for repairs" or "closed during overnight hours" or some kind of indicator that membership upgrade would not be available? Though I'm pleased with the outcome, I'm sure that runaround will happen to someone else. It should be fixed or mitigated so there won't be any more victims.