Abisko is a research-station village of well under a hundred residents, so the night here means the bar at the tourist station, a chairlift up the mountain and whatever the sky is doing.
Restaurang Kungsleden, STF Abisko Turiststation
The restaurant and bar at the Swedish Tourist Association station, open year round for breakfast, lunch and dinner; in practice it is the village's only reliable evening drink. Dinner bookings and dietary requests on +46 10 190 2403, and the train platform is a five-minute walk away.
Aurora Sky Station
STF-run chairlift up Nuolja to about 900 m, open in the evenings through the aurora season and for the midnight sun in summer, with an optional aurora dinner at the top. It is cold and exposed and warm overalls are handed out; booking on +46 10 190 2360.
Northern-lights tours from Abisko Guesthouse
Hostel and husky operation in the village running evening northern-lights outings and dog sledding in winter, plus day activities in summer. Useful if you would rather be driven away from the station's lights than stand outside the hotel.
There is no Systembolaget in Abisko
Sweden sells anything above 3.5% only through the state off-licence, and the nearest branch is in Kiruna, about 100 km east down the E10. If you want wine or spirits in your cabin, buy them before you get on the train; otherwise you are drinking at tourist-station bar prices.
The season decides whether there is a night at all
From late May to mid-July the sun does not set, so there is no darkness to drink in and people hike instead; in December it does not rise, and the aurora season runs roughly September to March. Plan the trip around which of those you actually want.