If you fancy york Jessop have a browse through the accomodation on
http://www.visityork.org .you will find some that do 1 night bookings you just need to persevere

. or how about the travelodge at york . there is one right in the centre and im sure you could do a 1 night booking there. You can search for available accomodation on that site jessop . not sure what night you wanted but just did a quick search for fri 7th for city centre and there were several guest houses that came up . if there was anything that you fancied it maybe easier to ring them direct and you can always check them out on the tripadvisor review site

.I spent an afternoon ringing round numerous york guest houses last year for a one night stay in a family room for 5 and i did eventually find one . i would recommend something in the city centre or walkable though as parking would be hard to find.
lyn
crikey just had a look at the travelodge . £75 and you dont even get breakfast , you can definately do better than that . We always stay at the blue bridge hotel which is a lovely 10 min walk along the river.it gets mixed reviews but we have always been happy and you get a good breakfast