I have a 2011 V70 D5 for this exact type of driving.
Circa 22K a year which is mainly motorway albeit not at motorway speeds generally due to traffic (M25).
Its the most comfortable car I have been in, granted my experience here is not ideal but it seemed better than (e46 3 series, new 5/6 series although both were M Sports), other cars were S2K, Astra VXR, MX5 etc which dont really compare.
I never feel tired or ache regardless of journey time.
Mines automatic and I get around 41MPG if I drive it nicely, getting around 550-650 per tank depending on use.
It has decent performance and touch wood, bar the aux belt going which is a common issue, has been faultless. Make sure you have warranty on this age car or get the AUX belt changed. I was lucky but it can split, wrap around the drive belt and kill the engine.
I got it at 30K and its now just below 70K.
The only thing really wrong with it is the MPG, I could be getting better but the Volvo is just a nice place to be and I value that as I spend up to 3 hours a day in it.