Getting there - nearest airport is Geneva (1 hr 20 mins drive from the chalets). All London airports, Bristol, East Midlands, Southampton and others fly there with airlines such as Easy jet, Swiss Air, British Airways, Flybe.
Car hire at the Swiss side of the airport (if you rent from the French side you will have to negotiate the centre of Geneva which is not advisable!) can be arranged in advance through (holiday autos). Follow signs to France, then Chamonix Mt Blanc and then Argentiere. From there look at the map opposite and park in the car park opposite the Hotel Buet.