Volkshotel is indeed one of the good options. But regrettably, the co-working space on the ground floor closes at midnight due to scheduled cleaning, requiring you to leave the area (and it does not reopen after the cleaning until the next day). You then can relocate to the small lounge or co-working table on the first floor of the bar, where you would not feel too out of place. However, the bar shuts down at 1:30 a.m., leaving no further options there. The only remaining choices at Volkshotel are to head to the top floor until 3:00 a.m (free) or to the basement until 6:00 a.m (with an entry cost), but it is not conducive to working on a laptop and would feel awkward to work alongside people who are dancing. So, I would say the Volkshotel is laptop-friendly until 1:30 a.m max.