There's also a nice campsite with cabins in Hahndorf - no idea what the prices are but worth a look.

Don't be put off by horror stories of housesitting either - I know lots of people who have done it successfully (including a few from this site) and with people taking their main holidays that time of year from here, would think it's a good time to do it. You might even find someone from here who is planning a trip away that time of year and needs a house/pet sitter.