[Brekkie]

I know it's not unusual for shows to give away six figure sums but £100k is too much for Wheel of Fortune.

Yes but if they use the US format it would need to randomly be won in the main game and the final prize selection.

I think they put a token on the main wheel, which if landed on adds it to the possible prizes in the final (but only if that player wins and doesn't go bankrupt), and then it's one of 20 or so prizes that can be randomly selected as the jackpot in the final, and then it actually has to be won. So there is probably something like a 0.1% chance it can be won. The $1m has only been won 4 times in 15 years in the US (so in around 3000 episodes).