Thanks both of you, I really wish I had gone into linux, however I am still on Windows. Which means I have no clue how to do anything of what you just said, even if it looks simple when you put it that way.
I just have no idea how to fetch the addresses from the blockchain. If I would have that I could probably figure something out.

BTCrecover from Python is really solid, already got all addresses, already got the generating program, does 18k addresses through blockchain per second with a wallet depth of 10
All I need is to figure out how to feed it my own set of privatekeys/seedlist.

Which would mean at MOST
7 hours with 12 words,
4 days with 13 words,
28 days with 14 words,
140 days with 15 words and 17 terrabytes of seeds.

I could live with that.

EDIT: That would be including all with wrong checksum, the correct checksum would only be 5% of these.

EDIT 2:
Day 14 of problem solving.

I have now started to generate all combinations. I settled with the 14 words I am most confident about.
This give me 43 589 145 600 combinations, I have three words I am certain about, which brings the combinations down to about 20 000 000 000 combinations.
This totals at some 1.6 Terrabytes of data. Only problem left is to feed it to btcrecover.