I had a great trip to Boundary Peak about 15 years ago.
We went up in the afternoon, made camp at a small snowfield that had just enough run-off to get water, and summited boundary as well as Montgomery the next morning, piece of cake, down for dinner.
What was the secret?
I went with Bob Failing who already had done it, or had a miserable time failing, so he already knew the way. That's the trick.... get some fool who has already done it to go back again!