What would be the best option for transport of 4 adults and luggage at this hour?
Your hotel can probably arrange a taxi.
The good news is that traffic should be light………
Our hotel arranged a taxi for us in an almost identical situation 2 years ago. Even though the hotel was in a pedestrian zone, the taxi was able to come to the front door at that time of day.
I had a 6am flight last Tuesday. Hotel got me a taxi. I was there at 5am. Just me, myself and I. Airport opens at 5am so the 2-3 hours ahead just doesn't work.