Exclusive first ride: 2020 Bentley Continental Flying Spur

But as a global model that should prove popular not least in Russia, there are also more prosaic issues that demand cold-weather testing: does the parking brake freeze on overnight? Do the touchscreens struggle to wake up? Does the screenwash freeze as it hits the windshield? Equally, if snow packs the grille, snuffles a sensor and leads to catastrophic engine overheating, it’s unlikely to go down well with customers who have paid for the last word in luxury and sophistication.

“From a functional point of view, we also look at the stability control and the traction management,” Sprenger continues as we pass a convoy of similarly disguised BMWs travelling in the opposite direction. It all sounds predictable enough, but the reality can be treacherous. Four-wheel drive, winter tyres and a good 12 inches injected into the already generous wheelbase of the Continental GT coupé make for massive innate stability in the ‘Flying Spur’ (official name tbc), but lose control and such a vastly heavy car will go through the roadside snow banks like a wrecking ball through a stained-glass window. It does occasionally happen – how, you have to wonder, could it not? – which is why there’s rope in the boot of the Bentayga.

There are broader concerns in the minds of the engineers, however. The new car will battle the Mercedes-Maybach S600 and an overhauled Rolls-Royce Ghost, each in their own ways pretty spectacular. And as a Bentley, we would expect it to drive more sweetly than either.

Bentley will also look to push this new model into a higher price bracket than before, around the £200,000 mark, according to CEO Adrian Hallmark, and as such it will need to justify that expense with a commensurately lavish interior and splendid rolling refinement. The revised design should help: even on our cladded-up mule, it’s obvious the new car will cut a sharper, more athletic and more powerful stance than the old Flying Spur. The bevelled snout sits prouder, the grille more upright and yet the roofline is lower. An opportunistic glimpse at an undisguised 3D graphic of the car – shown on its own infotainment display – also reveals the sleek line of the raked rear windscreen and bootlid, which bears a striking resemblance to that of the handsome 2008 Brooklands Coupé.

Performance? A known quantity. Bentley will offer its twin-turbocharged 6.0-litre W12 and 4.0-litre V8 engines, with a 2.9-litre V6 plug-in hybrid powertrain expected to satisfy more punitively taxed markets, namely China. I’m told the W12 will be transplanted directly from the Continental GT, with 626bhp and a heroic 664lb ft delivered from a whisker over 1300rpm. Out here, Sprenger can usefully deploy barely a third of those totals on the road, but their latency is palpable and reassuring and ultimately adds to a pervasive sense of wellbeing. The official top speed is likely to be quoted at around 200mph, although one engineer quietly mentions some prototypes are already lapping Nardò in excess of 225mph.

Delays to the Continental GT have had a knock-on effect for the Spur programme, and tuning Porsche’s dual-clutch automatic gearbox for imperceptibly smooth shifts has also taken longer than expected, but, in this final season of winter testing, they seem to have that cracked. Elsewhere, the Stuttgart connection runs deep. As the ‘platform owner’ of this MSB chassis, Porsche had the ultimate say on the parameters, although Bentley was involved from the start of development and as such there’s greater built-in provision for wheel-travel – crucial for comfort.

In any case, the benefits of using a Porsche platform are evident once we’re out on the polished ice of the Arctic Falls proving ground at Lillkorsträsk. A farm during the summer months, in winter the lake is painstakingly prepared for the manufacturers – three days’ TLC for just a morning’s testing – and a test track is carved through the surrounding fields. Naturally, massive drifts ensue, but it’s the way the steering follows the slip angle of the car, with the chassis then deftly pulling itself straight under power, that highlights the neutrality of the chassis. Before you ask, I can actually see this happening, because Sprenger repeatedly throws the car sideways then removes his hands from the wheel entirely, to no ill effect. He won’t be drawn on specific rivals but softly remarks that there are cars out in the field that don’t do that – once you get unstable, they exaggerate the movements.