M62 steve
i did this in 2005 as my first ever marathon. decided in june of that year to do it and was then half marathon fit. SO no reason why you cant if you put in the right training. you've awhile yet so don't peak too soon and get a good baseline in . you'll need to do hill work too.
don't be put off, this is a great race. spectactular. i'm coming back for thirds (in a row). can't wait.
prsonally think saturday is great. means can stay over after the race, not hurry back, and have a few welsh ales to ease the aching limbs!