You have hit on a common problem. Training for distinct and divergent goals always presents challenges and mean you will have to compromise someplace unless you are already at a very high level of fitness. As you see the Ice and Mixed plan is an upper body/core strength based training program. The 24 week plan on the other hand is an aerobically based plan using strength training as a supplement to all the aerobic work. Just doing both plans at the same time will be a big time commitment and test your ability to recover. Maximizing improvement in diverse areas like these two takes a serial approach over the course of years. Best gains will come when emphasize one are of another for some period while doing maintenance in the other then switch the emphasis for the next period. Over years you will become better in both.
A workable compromise for this ice season is to begin the aerobic parts of the 25 week plan now doing as much of that as you can handle/fit in while doing the strength from the I&M plan. The leg strength training progression of the 24 week plan has a very specific purpose and while you can go straight the later weeks of muscular endurance and see gains (like if you started the ME in say Feb) you will not see your best results in Denali type strength/endurance. This would still be how I would recommend you compromise your training IF the ice season is most important.
It is very hard to give this advice without knowing how fit you are in either of these areas currently.