Just had good results with
Airalo ESIM (you choose your region and your GB limit, it's refillable and less trouble than signing up for a cell plan). I bought the EU region to cover time I would spend in France, Spain and Portugal. If you can use an ESIM in your phone, look into this.
I found also that more and more frequently I used my TAP electronic payment (definitely a post CoViD change) and only took out a very limited amount of cash this time (400 euros for 5 weeks and I came home with 75 euros in cash in my pocket).
I think folks coming from the US can do really well on Charles Schwab... and when you need to, use electronic payment (just make sure you choose "euros" for your currency so that you get the best exchange rate).