If you have a time to walk your Dane normally, you'll have perfect dog!
My angel is wonderful in every apartment we have been in. As long as they get plenty of attention and enough time to exercise outside, you will have a happy dane no matter what. All they care about is being with you.
Danes are mostly couch potatoes. As long as they get a walk and a little play time each day, they do fine. As the other person said, they just want to be with you. Mine is almost a year old and still follows me around like a little puppy.
As others have said couch potatoes. I am a truck driver and have a Dane in the truck with me. So they don't need a lot of room and some might say. He has been on the truck with me for the last 7 years.