It's hard to say this far out, as a late May storm could cause problems, but section 1/2 are one of the most likely parts to be snow-free-ish, because of the lower elevation. Kenosha and afterwards does take a bit more time to melt out.
The CTF FB page usually posts snow condition reports by section. The usual suggested start date for a thru
hike is no earlier than ~July 1st.
https://www.facebook.com/ColoradoTrailFoundation/
