Occasional high mileage on 1.0 2014 Toyota Vitz

Hi there, I am about to purchase a 1.0 litre japanese import Toyota Vitz. On weekdays I have a relatively short commute to work which is about 4km(2.5miles)each way and possibly other errands within a small town which will probably get me to 50km(31miles)a week. Maybe once or twice month I might head down to my home town via a motorway and it’s going to be about 170km(105miles) one way on about 120km/hr roads. I just wanted to ask the more experienced drivers, will this be too much stress on the small engine? Would it be better to get a bigger car in terms of engine size or am I exaggerating?

thanks