Best I've come up with just the one change at Birmingham and valid from Bristol at 0830 onward is:
Bristol
TM‡ - Cheltenham Spa Off Peak Day Return
^7.80Stonehouse - Bromsgrove Off Peak Day Return
^10.10 (*see note)
Birmingham NS - Wolverhampton Off Peak Day Return (Virgin trains only)
^3.20Wolverhampton - Crewe Off Peak Return
^16.10Crewe - Wigan NW Anytime Day Return
^13.40Wigan NW - Preston Anytime Day Return
^6.60Total ^57.20*Note: The Stonehouse to Bromsgrove Off Peak Day Return fare allows travel via Birmingham New Street thanks to a double-back easement in the Routeing Guide:
300422 Customers travelling from Bromsgrove via Cheltenham Spa may travel via Birmingham New Street. This easement applies in both directions.
The ticket conditions allow you to 'start, or break and resume, a journey (in either direction in the case of a return ticket) at any intermediate station, as long as the ticket you hold is valid for the trains you
want to use. You may also end your journey (in either direction in the case of a return ticket) before the destination shown on the ticket.'
As there is a Routeing Guide easement in place allowing travel via Birmingham NS, then its fine to use the Stonehouse - Bromsgrove ticket to travel 'short' to Birmingham NS. Worth being armed with this information though - A printout from the relevant
Routeing Guide easement. I've been queried twice by
XC▸ guards when holding a ticket to Bromsgrove - both times they were happy to let me travel once I'd explained about the easement. No need to tell them know you're not actually going to Bromsgrove though!
And why Stonehouse? Because its 30p cheaper to buy the ticket from there than the Cheltenham Spa - Bromsgrove fare. I've only just discovered that! So you're actually starting short and ending short on that fare.
As I mentioned this combination of tickets is valid from Bristol at or after 0830.
0830 Bristol Temple Meads - Birmingham New Street 0956 (XC)
1012 Birmingham New Street - Preston 1151 (
VT▸ )
Now you can combine my first two tickets with your idea of splits at Wolverhampton, Stoke and Manchester and save another ^5 or so, but starting Off Peak at Bristol at 0830 (two changes) or 0900 (one change) will not get you to Preston until 1255.