I got this and the only issue is size of the full screen. Once installed go to manage bottles, control panel, launch the wine config, select the graphic tab, and uncheck both "allow the window manager to decorate the windows" and "allow the window manager to control the windows". Once this is done the game runs perfect on full screen. Enjoy.
I did those changes and when I launch Baldur's Gate 2 and I still get the white screen cant play.
After uncheking those go to the actual game config icon and open the BG2 config. In there try to find the area where it mentions 3 options of BLT or something like it. I think is the last Tab, have a check mark on those and the game should run perfectly.
Edit: yes is the last selection the 2d 3d options, in there on the 2d options on top check all 3 areas of BLT, also make sure the game is on 2D and not 3D. Happy gaming.