post electrification where will the 185s go?
As Paul Sidorczuk and ainsworth74 have already said, nobody really knows. My own thoughts on the matter (not that anyone cares!) are...
If the TPE franchise is to lose DMUs then the two coach 170s would be the first to leave (partly because they are shorter, partly because they are "non standard" at TPE, partly because they could fit into the FSR/ GA/ SN*/ LM/ XC fleet fairly easily)
There will still be unelectrified lines currently served by 185s at the end of CP5 - almost the entire Cleethorpes route plus Barrow, Windermere, Middlesbrough, Scarborough... even if Hull is wired soon, so they'll presumably still be needed in northern England.
If there are some spared (after doubling up existing services to cope with increased demand over the rest of the decade) then I think it'd be easiest to move the 185s onto hilly routes in the same area - Manchester to Buxton, Calder Valley, Blackpool to Leeds/ York/ Scarborough.
Beyond that, look at medium/long distance 90/100mph routes where a three coach train would be an advantage on what currently runs - like the two coach NR 156s on Newcastle - Carlisle or two coach NR 158s on Leeds - Nottingham or the two coach ATW 175s on Manchester services.
However I'm not convinced by splitting the fleet up, given that it's not a huge fleet in the first place.
(* - with different couplers)