Subject: Re: Euro bank for US citizens?
I obtained a Portuguese bank account at Novobanco with the help of my Lisbon-based immigration lawyer, done entirely remotely. I believe Millennium in PT is also still opening accounts for US citizens, sometimes.

I suspect you'll find the answer is specific by country and your particular circumstances (my Portuguese long-term visa was just approved a few days ago).

After arrival I'll work on setting up brokerage accounts with EU brokers, as well. I don't expect that to be easy, and I expect Americans will be increasingly less important and less welcome in Europe in the future, as well.