Jamie,

Given what you said about your fitness level, I think a 14 mile day is expecting WAY too much in Colorado. Most people average about 1.5 miles an hour including rest stops. Few people plan for a 14 mile day unless they are in top shape.

That time of year, I would plan on spending the night at a campsite near a road. Each valley/drainage can form its own weather system and dump a load of snow during the night. If the wind is in the wrong direction, it will cover any trail markers. When the trails are snow covered, it's easy to go down an animal trail and end up lost.

If you can get to the Leadville Hostel (in Leadville, of course,) http://www.leadvillehostel.com/ the owner will be able to give you a ride to many trailheads on the Colorado Trail. You do have to spend the night there to get rides.(It's not too expensive.) You can also take the free bus to the trailheads in Breckenridge and Copper mountain. This will give you a wide range of options along the Colorado Trail and other trails. You can usually get good reports on the conditions on the Colorado Trail at www.trailforums.com.

In my opinion, Isolation Peak is a survival situation waiting to happen unless you are skilled in winter backpacking and winter navigation. It will only take a short period of snow to make the trail too slippery to descend safely.