With room to spare. The whole point is to free space.

Yes, DAB uses less bandwidth than FM, this is more or less its only advantage.

It also uses a bit less power at the transmitter, but the receivers are more complex and need more power than FM receivers (afaik), which is a bad tradeoff.

If it works, the sound quality is amazing compared to FM and you do get a modern system with almost instant setup, a proper list of channels etcetera.