Yup, later will be safer than early and there's simply no way to know. Snowpacks are over 200% of average in some basins.

A hot summer will clear most out; a mild summer means a lot of snow will linger until next winter. I'll guess the north slopes of the higher JMT passes will have snow through the season, but they'll get heavy travel too.

I feel sorry for NOBO PCT thruhikers!

Cheers,
_________________________
--Rick