I have an opportunity to live in France with a host family and teach them English for 8 weeks. As it stands I have almost no working knowledge of French and the trip will be in about 2 months. The only requirement is to have a good basic, lower intermediate use of the language.

So.. providing I have been learning German for 2 years and have that experience to draw upon. Do I have a realistic chance of meeting this requirement in 2 months?

Also If i do, would living there for 8 weeks make any significant improvement?

If you really want it, you can do it. But you will have to do it full time.

By full time, how many hours per week are you suggesting? Also what methods, LingQ?

By full time I mean pretty much every waking moment that you are in contact with any language you should organise your life so it is French. LingQ would be great for doing that but with this sort of strategy variety is key. So anything that suits you, even if it seems crazy, but make sure it is in French. I would sit down now with a calender and try to plan how that would work. Make lists of websites, buy books. Get some music. etc

If it were me, my focus would be listening to and reading comprehensible content. I would also listen frequently to content that I like. I would save key expressions and review them in the vocabulary area. I would listen as much as possible. Don't worry about what you can say. Focus on being able to understand. The more you understand, the better you will do once you are there. The speaking will come quite quickly on the ground if you can understand. Good luck. Bon courage et bonne chance!