AH, will always sponsor you. Good news that running is feeling easier, after epic long run, XC and Yassos sounds nice progression and no coughing too. And as for the naughty old dog comments by Ikle, you're always learning new tricks so definitely not right
Top dog?
Tutu, lovely to see you back.
Susan I assume is sunning herself by pool whilst we all freeze.
Agent Ginger welcome. As AH says, its too early now. Best to take it easy now, and base your pace on a half marathon nearer the time, March or whenever. Its a bit of a stretch to jump from 5hrs to sub 4 unless you show that improvement on 10k & half times. Oh and P&D is a bit anal as plans go. Mad speed and high mileage - not really recommended.
Oliver & Tom, you're in the same boat, best advice someone gave me last year was to do my first 2-3 long runs at rough marathon pace plus 90 seconds... felt soo slow. But it really works especially for men. great advice from AH too, solid gold. Tom - zero tablets are ace but gels have electrolytes in anyway. Clif shots for me.
mcs, great run.. see below, sounds similar. also looking at the speedcross.
League race for me at weekend, cold and although in a park, very twisty turny which I find hard, and on a camber / angled path the whole time which I don't like from old injury left hip & heel... (AH you are not alone!) 4 laps going left the whole time... grrr. 5.5 miles in 35 minutes, roughly 6.30min miles, not too shabby but not flat out pace either - Jan is more a month for LOOOONG stuff in my plan. Then 6 ish miles warm down with friends to our house, sausages sizzling in the AGA, bacon, tea.. lovely!
Light stuff only this week, then a busy weekend - final preparation for the ultra - with Jovi - or at least it was till today. 
Saturday doing Hebden Bridge 22 miler with my missus at her pace, hilly and also expecting snow. Backpacks, jackets, trail shoes and tons of lovely food every 3-4 miles, plus a full meal and dessert with custard at the end. Hills estimated approx 3500-4000 ft. Call me mad, but it will be FUN.
Then Sunday doing Helsby Half marathon as a training run, pace to be decided. Maybe try and meet LO65.