If I were in this situation I would approach it from a somewhat different angle. Taking three steps:
1. Stay where you are and use the funding to create a demonstrable MVP.
2. Once the MVP is ready for demonstrations, then visit SV/USA on a B1 visa. Conduct the meetings, demo the MVP AND negotiate next round funding. As required for a B1 do not actually work on the product whilst in the USA.
3. Assuming you get $2m+ for round 2, then you return home, get the appropriate visa lined up and then make the move. While waiting for the wheels of bureaucrazy to grind by, you would do further work on your product.
As many comments suggest, $100k won't last long in SV. Immigration legal services don't come cheap either. Immigration process takes a long time to complete appropriately. You will waste a lot of time and money relocating. If you don't get a substantial second round of funding you will have to pack up and go back to EU.