Short distances with a 645i?

Hello together after I sold my 325 i Coupe, I would like to get a Bmw 645i 8 cylinder. Problem is my work is only 5 km away and I drive around in the leisure time if at all 15 km in the area. 14000km in the year always short distances. I absolutely want a 6 but would not drive through the short distances the engine broken especially in winter ? With my old Coupe I had nice problems with hydrostoes so the clacking in the cold start. Detour to work ok Environmentally friendly isn’t that but the main thing is a 6 thanks for your answers