I think it is relatively straightforward to determine from the Railway Codes ELR information. While Realtimetrains says "Gresty Green Through Sdg", Railmiles has it as "Crewe Gresty Green Up Loop" but no mileage.
London Euston to Crewe is on line LEC
Stafford is at 133mi 43ch from London Euston (source
http://www.railwaycodes.org.uk/elrs/_mileages/l/lec3.shtm)
Basford Hall Junction is at 156mi 16ch from London Euston (source
http://www.railwaycodes.org.uk/elrs/_mileages/l/lec4.shtm)
Onto line BHI
Salop Goods Loop Junction is at 157mi 26ch from London Euston (source
http://www.railwaycodes.org.uk/elrs/_mileages/b/bhi.shtm)
Onto line CSG
Gresty Lane Junction is at 157mi 55ch from London Euston (source
http://www.railwaycodes.org.uk/elrs/_mileages/c/csg.shtm)
Onto line SYC
Gresty Lane Junction (connection from line CSG) is at 0mi 41ch from Crewe South Junction (source
http://www.railwaycodes.org.uk/elrs/_mileages/s/syc.shtm)
Then Gresty Green Up Loop isn't recorded.
I assume it is Gresty Green East at 0mi 60ch
From that, I reckon Stafford to Crewe Gresty Green Up Loop must be 24mi 31ch. Railmiles suggests that Hereford - Selly Oak - Aston - Walsall - Stafford is 91mi 74ch so I make the total
116mi 25ch
Going back into Crewe, it is the distance from Gresty Green East to Crewe South Junction of 0mi 60ch and Crewe to Crewe South Junction which is 1mi 20 ch (source
http://www.railwaycodes.org.uk/elrs/_mileages/l/lec5.shtm) so
2mi in total.
I guess there will be confirmation in a fixture report at some point.