So like all these Omega replacement threads where the OP is a fussy bastid ( ) and they've limited their options to an 'Omega like car' you've narrowed it down to a BMW 5 series or Mercedes E class with engine of choice IMO. If you don't mind a slightly smaller car then the BMW 3 series or Mercedes C class.
Yup, I think that sums it up, and was the conclusion I came to. 5 Series/E class might be out of my price range though.
If you can let go of your RWD fixation then the Volvo V70 is excellent and for your ski trips then the AWD version or XC70 would be ideal.
From memory XC70 is statistically the second most likely to be written off or suffer major accident damage in the French Alps. BMW X5 is top. 4WD helps traction in slippy conditions, but does bu99er all for outright grip or stopping - especially when fitted with the rubber bands they laughingly call all season tyres.
Alternatively, we might know of someone who might be letting go of a nice sounding Subaru Forester in the near(ish?) future.
My Sister and BiL had a battered old Forrester when they did a winter season in New Zealand. Not a bad choice, but not for me thanks.