I've had teams bigger than that with a fixed 10 minute slot for standups, where the next team would have their standup after those 10 minutes. It was not a prob

I've had teams bigger than that with a fixed 10 minute slot for standups, where the next team would have their standup after those 10 minutes. It was not a problem, but it enforced meeting discipline. As for going off track, you will need to learn to tell people (including yourself) to take a time out and discuss matters after the standup. If anyone says more than a sentence or two, and if there is more than a single counterquestion and a short answer, then that should be taken after the meeting.