How to Modify my Marathon Training?

I am following the Jeff Galloway Time Goal Training Program for Rome. It calls for a 23 miler on 1/28 and a 26 miler on 2/19

I know for sure I can't do 28 miles on 1/28. I am supporting a go-LIVE in Northern California for week, and I'm working 12 hour shifts everyday from Monday the 23rd through Sunday the 29th, and then have an 18 hour trip home to Maine on Monday. The other complication is that I am running the half marathon in the 26.2 with Donna on February 12, just a week before my 26 miler.

What to do?

Here's what I'm thinking, do a 13-15 miler this weekend (the 21st) to get in something longish which gives me 2 weekends of recovery before the half. Then push back the 26 miler to February 26. This gives me 2 weeks to recover from racing the half, but still 3 weeks to taper before the marathon.

What do you think? Will this work?