Not in a T8, but this range thing is the same for me.
Definitely based on current/recent consumption
Left Central London with 100 miles to refill, and 10 minutes after I hit the motorway (20 mins later) recalculated to 160 miles to refill.
Quite common - V50 was the same.
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Now looking for a MY2022/3 XC40 in SW France! 
MY19 XC60 T5 Momentum Intellisafe Pro, Xenium, Smartphone, Keyless, 4 zone, Tempa - Pine Grey w/ Charcoal leather.
Former V50 Owner
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