Winter running = lots of laundry (+marathon training plan!)

One thing I've noticed about running in the winter is that it generates a lot of laundry because of all the layers and accessories (hats, gloves, etc). I'm doing a load of running stuff every two days it seems. Maybe for Christmas, I'll ask for some more gear so I don't have to do laundry as often....
Yesterday, I did an 8km run in the afternoon. When I left the house around 3:45, it was 12*C. By the time I got home around 4:45, it was dark and I was freezing! I couldn't believe how quickly things changed after the sun went down (4:08 was sunset, I believe).
Tonight was my usual spinning class, but sadly I couldn't go - I got called at the last minute to replace a sick teacher, who was supposed to do placement tests over the phone. Unfortunately, the tests were scheduled for the exact time of my spinning class and work takes priority over fun. I did, however, go out for a 5km afterwards, just a nice easy run. My average heart rate was only 171, with the max at 187. Now I know this might sound intense for some people, but for me, that's an easy effort. According to my Garmin, the whole run was in zones 1 and 2 - a first, I believe.
This morning, while I was waiting for the technicians to do their work in the basement (stage 6 million in the epic furnace replacement saga), I finally settled on a marathon training plan. It's the Hal Higdon Novice 2 plan, with paces taken from McMillian Running. It looks much cooler in OneNote, where I have check-boxes for each of my workouts, but here it is:

Week	of	Easy	Speed	Easy	Long	Cross-Training (min. 1hr)	Weights
1	Jan. 23	5km @7:07-7:26	8km  @6:12-6:28	5km @7:07-7:26	13km  @7:07-7:45
2	Jan. 30	5km @7:07-7:26	8km  @7:07-7:26	5km @7:07-7:26	15km  @7:07-7:45
3	Feb. 6	5km @7:07-7:26	8km  @6:12-6:28	5km @7:07-7:26	10km  @7:07-7:45
4	Feb. 13	5km @7:07-7:26	10km @6:12-6:28	5km  @7:07-7:26	18km  @7:07-7:45
5	Feb. 20	5km @7:07-7:26	10km @7:07-7:26	5km @7:07-7:26	20km  @7:07-7:45
6	Feb. 27	5km @7:07-7:26	10km @6:12-6:28	5km @7:07-7:26	15km  @7:07-7:45
7	March 5	7km @7:07-7:26	11km @6:12-6:28	7km @7:07-7:26	23km  @7:07-7:45
8	March 12	7km @7:07-7:26	7km  @7:07-7:26	7km @7:07-7:26	24km  @7:07-7:45
9	March 19	7km @7:07-7:26	11km @6:12-6:28	7km @7:07-7:26	Half Marathon
10	March 26	7km @7:07-7:26	13km @6:12-6:28	7km @7:07-7:26	27km  @7:07-7:45
11	April 2	8km @7:07-7:26	13km @7:07-7:26	8km @7:07-7:26	29km  @7:07-7:45
12	April 9	8km @7:07-7:26	13km @6:12-6:28	8km @7:07-7:26	21km  @7:07-7:45
13	April 16	8km @7:07-7:26	8km  @6:12-6:28	8km @7:07-7:26	31km  @7:07-7:45
14	April 23	8km @7:07-7:26	13km @7:07-7:26	8km @7:07-7:26	20km  @7:07-7:45
15	April 30	8km @7:07-7:26	8km @6:12-6:28	8km @7:07-7:26	32km  @7:07-7:45
16	May 7	8km @7:07-7:26	7km  @6:12-6:28	8km @7:07-7:26	20km  @7:07-7:45
17	May 14	7km @7:07-7:26	5km  @7:07-7:26	7km @7:07-7:26	8km  @7:07-7:45
18	May 21	5km @7:07-7:26	3km  @7:07-7:26	3km @7:07-7:26	Ottawa Marathon

I plan on doing at least 1 cross-training workout/week as well as a strength workout. I was also looking at the Intermediate 1 plan, which adds a 5th day of running, but I wasn't sure if that'd be too much. Any thoughts?