That's got me quite curious - what's in Sunderland at that time of morning (if you don't mind me asking that is)?....
Might let you know what I'm up to nearer the time.
I think my silence so far on the matter says all that needs to be said about the quantity (and quality) of overnight accomodation in Sunderland.

There's a few B&Bs towards the seafront around Roker, in the vicinity of Park Parade, but to my knowledge there isn't very much else at all within close range of the city centre. So similar to what you suggest really....
Quality isn't overly important, I won't be there long, and I only need one, so quantity is overly important either.
....There is of course the Travelodge on the west side of the city centre, but given that it is located above the rowdiest Wetherspoons in Sunderland on one side and faces out over the closest thing Sunderland has to a ring road on the other I wouldn't recommend it for a good nights' sleep.
To be honest I can sleep through quite a bit, people snoring, drunks, fire alarms, and yet I always hear my alarm clock, no matter how tired I am.
Good choice sir! There is a far wider range of guest houses in Plymouth, and there are some very cheap ones, especially out of season. I ha done a few years ago for £20 a night, called The Elizabethan or soemthing like that IIRC. Admittedly it wasn't close to the station, but I think there are a few round the North Road area as well.
A quick search shows some rooms for £28pn which beats pretty much anything in Par and Exmouth by some distance. I can't really stray too far from the station for this one though, I'm not likely to get to the station before 2130!
Blackpool South to North. Around 40 minutes walk. Allow 1hr train to train.
Tram does't save much time. Up steps, and turn left.
Take either a No 5 or 11 bus from Royal Oak roundabout. Stops are outside the 2 Chemist shops. Alight Town Centre - Cliften St or Talbot Road by Home Bargains. There are no stops near North station, except for No 16 that calls in North station yard. It also leaves from South Shore but is a slow & not obvious route!....
I might have to walk fast, 50 minutes train to train is the best I can do (well aside from 1 hour 50 minutes).
....Blackpool has plentiful cheap accommodation. Avoid Central Travelodge, unless you like the bass beat from the 2 nightclubs below!!!....
I won't have to stay in Blackpool on this trip fortunately.
....Plymouth - there are several guest houses near the Hoe A good 20 minutes walk.
Uphill out of North Road Station, straight down though the underpasses keep going straight through shopping area, Hoe dead ahead. Very pleasant part of Plymouth! Allow 40 minutes to catch train from Hoe.
(If you turn to the left along seafront there are some good pubs in the Barbican area.)
Thanks I'll have a look at that.