a co-worker will travel to a convention in Hannover which takes place in the Congress Hotel Hannover. She doesn't want to stay right there and would like a place that's close to it, clean, budget is preferably below 60 Euro per night for single room. She's not a big breakfast eater so if there is a bakery or cafe nearby where she can have a coffee and croissant that's fine.
How is the area around Hauptbahnhof, btw? Recommended to stay there?
Thanks in advance!