Got to say that I experienced this first hand, as a passenger, and it was an extremely well organised emergency bus replacement. Despite a massive queue at Preston, staff involved dealt with people very effectively, the queue kept moving and within an hour I was on a bus, less than two hours later in Carlisle.
Carlisle itself was something of a shambles as the forecourt just can’t cope with large volumes of buses, and they really need a better arrangement in future.
I waited just 10 minutes for a train north (actually formed of the double voyager which had done the rescue earlier in the day, and was forming a special service from Lancaster), but only caught that because the bus driver took pity on us and dropped us off short of the turning area at Carlisle Citadel, earning a boll@@king from the supervisor but everyone else’s heartfelt thanks.
edit to add: pretty sure that the second trapped pendolino was dragged back south by a loco off a freight that was in the loop at Broughton. Seemed to be how it worked watching on Opentimestrains. Carlisle thunderbird eventually rescuing the first trapped pendolino.