Dear T,
Please reply. Session is in 3 hours (assuming I have the time right), and I just want to know that it's still on (and that you know I want virtual). My subject line makes it clear what I'm asking. I just hope you got home OK and aren't, say, sick or anything. If I don't hear back in an hour or so, I'll text, but was just trying to be as non-intrusive as possible, in case, say, you got home late and were sleeping in. Or have a mountain of texts and emails to reply to from being away.
Love,
LT