If Holy Roman Empire plays after Germany, I think we should reject the demand to be safest.
We can get +9 normally or +12 with shared war.
The odds of our Great Scientist dying is very small, but possible.
I'm often more risk tolerant than the team, so they might be on your side, but this seems very, very safe. I don't like the thought of an uphill battle for Diplo. What if Bismarck demands more stuff like 500 gold or tech?