When those strong guys nail it on a hill in a group of 4 or 5, if you're trying to win the race and not just finish it, you likely need to do all that you can to hold the last of their wheels and try and recover on the far side of the hill.
Sounds like you probably don't have the speed/fitness to just TT away from the field, but you may be able to get away from a 5 field on a technical course if you get off the front in a technical portion of the course and can get out of sight. Probably won't be successful if the word "coasting" is in your mind mid-break. You will need to rely on higher corner speeds to suceed.
Also getting away in the last 10 minutes of a race if you aren't super fit (aka you're fit enough where you could have gone at anytime and likely stayed away) is pretty unlikely