At outstations, my (Middle East Airline) rules are that we are on duty only 1:00 prior to departure. However, buried away in the OMA is a company requirement 'not to be under the influence of drug/alcohol at any time while in uniform.
Some of our outstation hotels are quite a way from the airport and it is not uncommon to get a wake up call 3:30 prior to dep for transport 2:30 prior to dep.
It wasn't very long ago that one of our crew was (allegedly) 'met' getting out of the hotel elevator prior to checking out (2:45 prior to dep), blew over the limit and lost their job. Not sure about the licence as, technically, not on duty.
Be careful out there.