The meeting dinner will be at this restaurant:
Wednesday, 19:00
“Gościniec Polskie Pierogi” restaurant
(https://gosciniec.waw.pl/)
on Krakowskie Przedmieście 29 (please be aware they have several locations!)
Choose from the menu, pay for what you order
If you need a receipt, please inform a waiter before ordering
Regarding transportatiion, remember that uber in Warsaw is not expensive. Checking just now the fare from FUW to the restaurant is €4.80. for up to 4 people. It should be even cheaper from the (new) city center.
Thanks, and see you there!