[Tannaton]

I wouldn't worry at all if the car has been appropriately maintained. A 300 miles journey is probably much easier than 10 x 30 mile journeys as you would have all the start, stop, accelerating and braking.

FYI in my little fleet of Volvo's my 2003 165k mile XC90 is the most reliable thing ever (compared to 2016 XC60, 2008 XC70 and 2007 V50) and I use it for towing car trailers - i.e. 1.8 -> 2.2 tons.