Or should I say "(...) once too often" or "(...) one time too many" instead? Or perhaps, "queuing twice for a cup of coffee is one queue too many?"
My issue with once too many is that it makes once sound like a countable noun; and with too often is that is this context it sounds more natural to ask "how many times (...)" than "how often did you queue?" But I surely like once after twice.
And yes, in some cafés you have to queue to pay, and then join another queue to get served.