I happily report that new EXE file that Alex sent me indeed fixed the problem - I did not have to change anything in nVidia panel, and FOV is correct in 1920*1200 as it was before the patch.
You can see new screenshot:
http://b.imagehost.org/0688/Divinity2_TRYOUT_2010-12-13_16-49-13-00.jpgSo I assume Larian folks will release the patch the official way soon. Really happy with Larian support!