Worth getting two bikes if you can.
My commuter is a road bike, but its fixed gear with rack and panniers. It is just as quick as my two road bikes, uses same rims, lower spec tyres, but essentially is the same.
The only issue is you will get hissed off with a wet ass if you can't fit guards, much as I hate them they are essential for commuting every day.
I commuted on something similar, but that was years ago, but was able to put guards on it in winter. You will eat components commuting.
Commuters generally get knocked about a bit more, even OCD folk like me. I'd get a
Ribble winter bike for commuting and another for weekend. You could still get an Ultegra equipped best bike and a Ribble for that money