We visited one such refurbished manor (castle like) nearby Karnitz. There was a couple from Sweden that had acquired the manor and spent all they had to attempt to convert the property into a guest hotel.  As in the case of any old building that has no central heating or running water the problems of renovation mount quickly.

They had attempted to build bathrooms in each of the rooms and had to place the plumbing underneath floors that had been built up.  However, once they filled the tubs with water, they fell through the floors and all the work and money went down the drain.  They are using just one room now as a bar.  This room has a large fireplace to keep any (and there aren't many) guests warm.

There is little infrastructure in place to support any business or tourism so unless one has a lot of cash to bury into one of these manors it doesn't make sense to do so.