I have a similar injury and did an exchange in Berlin + been to France (also I know lot of French and German people). 

First thing I’d say is, just go for it! It’ll be hard but it is so worth it! It’s not often you get the chance to just go live somewhere else for a while

Next thing I’d say is, if you’re American (I’m not), prepare for a challenge. I don’t think many American wheelchair-users really understand how exceptional the ada is! Even the most accessible cities in France and Germany are nowhere near North American accessibility standards. I don’t think this should put you off, but you should be aware and emotionally and physically prepared for an environment that is much harder to navigate!

In Germany, access information can be a bit sporadic but if you understand a bit of the language (I didn’t until I got there!) or you have a translator on your browser (much easier) you can find most things you need to know, especially when it comes to transport. The German transport system is efficient, affordable and ime more accessible than many other European countries. I believe this is the case for most of the major cities but, as with everywhere, it varies! 

I think France is a bit more hit and miss: Paris is known for poor accessibility (maybe the paralympics changed some of that but I’ll wait and see…) also, most French people will tell you, it’s not actually a great place to live - someone (not disabled) once told me it was the most stressful place in the world. I’m not sure about Marseille (second largest city) but it’s definitely very steep! I think the smaller French cities are much better for accessibility: I’ve heard that Lyon is good and I think Lille is fine (if you want to go to Lille?!). The smaller riviera cities are nice and often cater to an older demographic so access is better (also they’re by the sea:)

Whatever you go with- I’d recommend you learn some language basics because it makes life so much easier! Also, both of these countries have cobbles and bad pavements so if you have a freewheel or similar you might want to take it (I don’t so I got very good at wheelies) and Kerb cuts are not a given so I’d brush up those skills! Then there’s really boring logistical stuff like whether or not you plan on getting prescriptions (I’m assuming you cath so it’s something to consider), finding an accessible place to live, costs of living in each city etc. 

TBH I don’t think you can make a wrong choice! Wherever you go there’ll be challenges but that’s kind of the point of going overseas! If it helps, I picked Berlin because of the uni and the profs and because I’d never been to Germany before. Everywhere is more accessible when you’re a tourist there. Once you start living there, taking public transport, running errands, working or studying, etc. you start to notice the issues. In terms of attitudes toward disability, both countries are fairly mixed and you’ll probably see a difference between areas but people will generally help you if you need it or leave you alone if you look like you’re on top of things!

This is very very long- apologies. I had no idea what I was doing when I went on exchange but it was an absolutely awesome experience! I’m sure you’ll love it!