I know of no log cabins but I could be out of date!
Try googling Black Forest Tourist Office and also the Tourist Offices of Freiburg, Titisee, Baden Baden and Freudenstadt. They should be able to send you brochures even if you write in English. Black Forest is
Schwarzwald in German.
Flights - Ryanair fly into Karlsruhe-Baden, Easyjet into Basel and there will be a City Air flight into Strasbourg from London City starting shortly. BA and Swiss fly into Basel.
Best way to get around is by train. If you hire a car make sure it has ALL WEATHER types as is required by law in Germany in the winter months Oct-April. If you hire a car from Basel the car hire companies will probably not know about this and you will have to be VERY FIRM. You will also have to make sure that any of the hire companies at Karlsruhe-Baden meet this requirement too. Ignorance is no defence in law over here.
Activities ... ski jumping, cross country skiing, snow shoes etc if there is any snow! Also good thermal baths in Baden Baden and other resorts (check in advance), plenty of good food, walking, hot wine and expensive souvenir shops!
