1st week
stage 1 Düsseldorf (Germany) ITT 13km - confirmed
stage 2 Düsseldorf - Verviers or Marche en Famenne (?) (Belgium?)
http://www.sudinfo.be/1582412/article/2016-05-27/le-tour-de-france-passera-par-verviers-en-2017
stage 3 Verviers or Marche-en-Famenne (Belgium) - Esch-sur-Alzette (Luxembourg)
http://www.lequotidien.lu/sports/une-arrivee-a-esch-sur-alzette-sur-le-tour-de-france-2017/
stage 4 Mondorf-les-Bains (Luxembourg) - (France)
- Planche des Belles Filles (1035m) MTF -- all but certain
https://www.francebleu.fr/infos/culture-loisirs/info-fb-besancon-tour-de-france-une-arrivee-la-planche-des-belles-filles-en-2017-1468918674
2nd week
Alps
Col d'Izoard 2360m MTF (?)
http://www.dici.fr/actu/2016/07/24/hautes-alpes-info-d-une-arrivee-tour-de-france-sommet-col-d-izoard-2360-m-2017-872384
low probability I guess. After the Galibier MTF other attempts to host a stage on a big col (Iséran, Madeleine, IIRC) went nowhere
Méribel (?) - old rumor
http://www.ledauphine.com/savoie/2015/09/19/meribel-et-brides-candidates-au-tour-de-france-2017-albertville-des-2016
3rd week
Pyrenees
nothing credible that I can find
(Port de Balès, Superbagnères and Luz Ardiden are mentioned in this article, for what it's worth:
http://www.ladepeche.fr/article/2016/07/27/2391763-2017-les-pyrenees-en-juge-de-paix.html
Add on.
stage 1 Düsseldorf (Germany) ITT 13km - confirmed
stage 2 Düsseldorf - Verviers or Marche en Famenne (?) (Belgium?)
http://www.sudinfo.be/1582412/article/2016-05-27/le-tour-de-france-passera-par-verviers-en-2017
stage 3 Verviers or Marche-en-Famenne (Belgium) - Esch-sur-Alzette (Luxembourg)
http://www.lequotidien.lu/sports/une-arrivee-a-esch-sur-alzette-sur-le-tour-de-france-2017/
stage 4 Mondorf-les-Bains (Luxembourg) - (France)
- Planche des Belles Filles (1035m) MTF -- all but certain
https://www.francebleu.fr/infos/culture-loisirs/info-fb-besancon-tour-de-france-une-arrivee-la-planche-des-belles-filles-en-2017-1468918674
2nd week
Alps
Col d'Izoard 2360m MTF (?)
http://www.dici.fr/actu/2016/07/24/hautes-alpes-info-d-une-arrivee-tour-de-france-sommet-col-d-izoard-2360-m-2017-872384
low probability I guess. After the Galibier MTF other attempts to host a stage on a big col (Iséran, Madeleine, IIRC) went nowhere
Méribel (?) - old rumor
http://www.ledauphine.com/savoie/2015/09/19/meribel-et-brides-candidates-au-tour-de-france-2017-albertville-des-2016
3rd week
Pyrenees
nothing credible that I can find
(Port de Balès, Superbagnères and Luz Ardiden are mentioned in this article, for what it's worth:
http://www.ladepeche.fr/article/2016/07/27/2391763-2017-les-pyrenees-en-juge-de-paix.html
Add on.