Accommodation: The venue is quite close to the city center so hotels/hostels in the city center are recommended so that you can experience Copenhagen at its best.
We often use this hotel http://www.hotelchristianiv.dk/en/. It should be possible to get a small discount if you mention that you are visiting DTU. The same might be true for Hotel Phoenix. If these hotels are fully booked then you can also try (http://hotelnora.dk/en/).
This hostel (http://generatorhostels.com/en/destinations/copenhagen/) is quite nice and around the corner from the above hotel.
Apart from that one can look for Cph city center hotels through Google maps and see if any of them have special discounts.
Social program: We will have a workshop dinner 20.30 on May 21st. It will be at Madklubben Bistro-de-Luxe, Store Kongensgade 66.