Electric cars are ideal for short commutes, but the prospect of endless charging stops made me nervous of the trek to south-western France for a family holiday – particularly with a long-suffering dog aboard. However, the BMW iX3's claims of more than 400 miles made it far more realistic, and I decided to mitigate my mileage by taking an overnight ferry to St Malo.

The plan was to blast down to Portsmouth for a quick top-up in the UK, but as we reached Brittany Ferries' check-in we had barely made a dent in the range so decided not to bother. The car was slapped with a sticker identifying it as an EV – they can't go alongside lorries inside the boat – and we boarded at 8.15pm, leaving time for a leisurely dinner then a good kip before rolling out on the other side.

It's a very civilised way to travel, although I was lucky to get the last pet-friendly cabin for the desirable overnight sailing. Note to self to book early next time.

I haven't got my head around BMW's Neue Klasse styling yet; it works well on the i3 saloon but is a bit ungainly on an SUV. That said, we struggled with Chris Bangle's Flame Surfacing when it arrived...

The doors shut with a rather un-BMW clang and the ride around town can be jittery, with plenty of wheel thump. As soon as you hit an autoroute, though, the iX3 comes into its own. There's a touch of wind rustling around the A-pillar, but it's otherwise serene. The ride settles beautifully, the seats are superb and it makes fast, unruffled progress.

We reached our overnight stop in Tours, 278 miles in, still showing 16% battery, and while I walked the dog it took on 81.58kWh for a very reasonable €28.63 (30p per kWh).

Usefully, as well as signage on the motorway telling you how far away the next charger is, there are petrol station-style boards at the stations announcing (very cheap) prices.

From Tours it was another fast autoroute run down to the beautiful Dordogne. On sweeping, undulating country roads, any doubts about whether the iX3 is a 'real' BMW were wiped away. It breathes with the sinuous and often rutted Tarmac, making it easy to get into a rhythm, the head-up display warning of upcoming corners like a silent rally navigator.

Sport settings made the ride too hard for my passengers, but the chassis composure even in Efficient mode is superb, the steering being beautifully weighted and fluid.

Only after a shopping trip was there a hitch, when the car gave a few random warnings and my phone was reluctant to tether. I thought nothing more of it, but this led to a stressful evening trip to Bordeaux airport to collect my daughter, accompanied by all manner of electrical glitches.

'Driver assistance restricted' flashed up and the sat-nav said 'Function only available when stationary' (I was), so I had to rely on Apple CarPlay.

Both the main touchscreen and the (otherwise excellent) Panoramic iDrive display kept going black, usually on approach to a junction on dark, remote country lanes.

Fortunately, it still drove fine...

After a final panic on the outskirts of Bordeaux when I couldn't find a charger, eventually paying a steep €31.90 for 51.4kWh at an autoroute services, I scooped up Elsa and got her safely back.

A software update the following morning appeared to cure whatever ailment the car had been suffering.

The iX3's breadth made it tricky to navigate the tight town-centre car park of Périgueux, but fortunately we escaped unscathed this time.

On the way back we stopped at a Tesla Supercharger. Oddly, it claimed to provide 329kW but the car wouldn't take more than 91kW for a lethargic 47-minute charge. But, like so many in France, this charging station was in the car park of a hypermarket – ideal for a spot of shopping.

With bags and dog taking up most of the boot, the iX3's frunk was a revelation. Ideal for temporarily stashing our pet's more aromatic rubbish, on the way home it also proved exactly the right size for wine bottles to stack neatly, taking a case and a half with room to spare.

Only in rural areas was charging an issue. Out for dinner in nearby Verteillac, we plugged in at a car park, but in over an hour the iX3 took on only 5.8kWh.

After that we decided to stick to out-of-town industrial parks, such as the Plug Inn near Poitiers, which offers 320kW charging and a key code for a lounge alongside, with super-fast wi-fi, air-con, clean loos and a coffee machine.

So good – and cheap – is this network that we opted for one more stop to brim the battery outside Caen before boarding Brittany Ferries' MV Guillaume de Normandie to Portsmouth.

This faster route is slightly less relaxed than the St Malo crossing but better for the return, because the 11.30pm sailing docks at 6.15am, so we were home in time for work.

A final top-up took our energy use to 450kWh across 1353 miles, or a round 3.0mpkWh – not bad for a fast cross-continental run, fully laden, in 40deg C heat with cold air blasting.

I've come away with two main conclusions. First, France is doing better than Britain with its EV infrastructure; and second, if the brilliant iX3 represents the future of electric motoring, bring it on.