Just received an email with word that this year's YVAA grand prix races have been announced - see http://www.yvaa.org/10GP.htm
They are usually 5-6 miles approx and as a rule multiterrain. The first one at Meltham on 7 March looks tempting - unless I'm mistaken its the same route as the Cinammon Lodge Chase which I personally found tougher than Meltham Cop Hill race.