Did you know Via Rail has a fleet of British Rail Gauge train cars?
They obtained them from a failed sleeper service through the Chunnel in the 90s. I rode with them on the Montréal to Halifax rail service called The Ocean. Part of a big rail journey I took this summer across eastern Canada and Europe.
There will be a Chinese or Japanese version of Race Across the World where a team boards HS2 at old oak common thinking it'll take them all the way to Inverness. How dissapointed they are when the service terminates a few miles up the road at Brum.