Under Condition 28.2 of the
National Rail Conditions of Travel (NRCoT) - i.e. for any reason, you cannot complete your journey as planned - every Train Company in a position to assist you
must do so. Practically speaking, that means that, where there are still other trains running which will enable you to complete your journey, you must be allowed to take these (and you can't be forced to pay anything extra just to complete your journey!).
There is a 9:15 Northern service to Wigan arriving at 10:01. That means I could board the 10:25 Virgin which is the train that I'm booked on from Preston. is this allowable?
I would suggest that it's not only allowable, but it is a sensible option and one that Northern are more or less under an obligation (see above) to accept. In all likelihood, I foresee no issue at all with this plan, since it is eminently reasonable (and you are still taking the booked long-distance train) and, it being a strike day, some form of general ticket acceptance will be in place and it is therefore most unlikely that you would be challenged in any way.
The 19:31 is not running either. Can I stay on to Warringtom and get a Northern/East Midlands to Lime Street. Alternatively, stay on to Crewe and go via Chester? That applies to the outward leg if Northern cancel more trains.
You can do whatever is reasonable - if possible, you should still take the services you have reservations for, and comply with your ticket's route/TOC restriction where possible. But ultimately the duty I outlined above is relevant here - even TOCs which your ticket would not ordinarily be valid on (if, say, you had a route "Virgin & Northern" ticket, not that this exists as far as I'm aware) are obliged to assist you if it is reasonably practicable to do so.
If you are in any doubt, there is no harm in contacting the relevant TOC(s) in advance and asking them what they would advise, or whether they would authorise your proposed changes. Even if they say no, this does not change your rights - but on the contrary, if they say "yes", that would be conclusive evidence in the very unlikely event you were challenged on your choice of route/services.
In a nutshell I've been sold an Advance return journey that can't be fulfilled by the provider on the trains specified.
For as long as the unions announce strikes with less advance notice than the timetable is published in advance, this will continue to happen. The way the situation is handled is far from ideal - instead of simply cancelling all relevant services in the timetable (so they can at least be seen so that people intending to travel on them know to choose other options), they are almost always just removed from the timetable. This can cause significant issues, for example if TOCs claim that no assistance need be rendered since "that train was never in the timetable", or similarly if they refuse compensation on that basis (despite having booked before the timetable was changed).
In all honesty there needs to be stricter rules around timetable changes. If the unions are to continue to be allowed to wield as much power as they do over the TOCs and the lives of passengers, certain conditions ought to be attached to this power. For instance, they should be forced to announce all strikes at least 6 weeks ahead (during the current period where timetables are ordinarily confirmed that far in advance) - and when this eventually changes back to the normal 12 weeks, they should give that much notice. It's simply not fair on ordinary passengers who get caught up in it.
Equally, the TOCs should be banned from removing (rather than cancelling) trains from the timetable in these situations; that way the resultant misunderstandings and refusals of assistance and/or compensation simply would not occur (and where they nevertheless continued there would be no excuse of "not knowing"). Of course the TOCs have a perverse interest in removing rather than cancelling trains - as they get charged penalties by Network Rail if they cancel a train, plus it impacts their reliability statistics (which can be linked to franchise penalties). None of this applies to removals from the timetable. That perverse interest should be removed, at least in the case of strike-related cancellations.
