The first week of my 2010 Training Plan completed with 7 good days of running and 68km done, all on snow and ice and much on the hills and trails of Wicklow. The foot didn't give me too much bother and apart from a sore achilles (which I'll watch) no danger signs so far.
This week has started equally good with 25km completed already on route to my plan of around 77km for this week and my long 16 week quest to the 10.5hours/126km mark on its way despite conditions.
I've found a good loop to do at work of around 10km and the training I got running on ice at Mount Royal in 2008 seems to be worth every penny as I hadn't had a single slip or near-miss yet. Sure the conditions slow you down, but I have been delighted to report faster Base Run splits than ever during the first 10 days of my 2010 training (my 2010 calendar started on Monday 28th December 2009).
So to be honest, there's no reason to resort to treadmills and indoor sports, find a good footing, dress well, and have a solid pair of trail runners you trust and you can match any conditions. In any case, I need to just get on with as I'll be flying to Fargo on the 17th for three weeks were conditions are significantly colder and snowier and during that period I'll be ramping up to well over 80km per week.
While I do plan to do only some of those outside (the rest will be done on steep gradients on the hotel treadmill to start uphill training for Pike's Peak as Fargo is flat as a pan-cake!), I know there's no reason to let any weather deter me. If I shied away from the Dublin weather there would be no chance of surviving the Fargo weather with my training plan intact!