Thanks for the replies. I would rather stay in Medan the night and get transport to BL the next morning. I’m sure by the time I get out of the airport it would be almost 21:00.
Is it easier to reach BL ( public/ shared transport) from Medan city or airport?
Well if you are at the airport you are not in Medan. You can take a taxi (around 150,000IDR) to a Medan city hotel (room from around 150,000IDR I think, I don't know for sure I don't stay in cheap places). Or you can take a train (around 100,000IDR) directly to the d'prima Hotel (around 4-500,000IDR), or an onward rickshaw from the train station (expect to get ripped off, around 50,000IDR, though 10,000IDR is nearer the mark) to a different hotel.
From the airport you are <5km to a few airport hotels Wings, Crew and Thong's Inn. I guess you can get a taxi to there from the airport. Room prices from 300,000IDR and up. There are probably some fleapit homestay in Lubuk Pakam or somewhere like that that would be less, but IDK.
If you stay the night in an airport hotel it will be less easy to catch a bus onwards, but maybe you can stop a bus I'm not really sure though, I guess taxis are more normal if you stay in an airport hotel.
If you go to the city then the next day you can head out to Kampung Lalang where you will meet some red-eyed meth fiends who will try and charge you around 100 or 150,000IDR for the 18,000IDR bus fare to Bukit Lawang.
A private car to Bukit Lawang should take 3 hours at that time, possibly slightly less if the driver has good technique for flying over the potholes. Possibly a bit longer on Saturdays, as there's a bit of traffic with people going out for Saturday night. So you should be there before midnight.
