The recent model boast between 40-60 mins, so I guess the question is how often one might want to empty it. We have their regular size bin, vacuum most days and empty around 3-time a week. The larger models have an even larger bin capacity, cover the same floor space/battery life, but I'd imagine you’d only empty it once or twice a week. 

If it were me picking, and cost wasn’t an issue, I'd buy their outsize model. If that isn’t available in your country, the either the Gen5 or the V15 is a good bet! 

Give their Help me choose | Vacuum cleaners (dyson.co.uk) a whirl.