That assumes that the Trail Ridge Road (US-34) will be open. This road which crosses the Rockies at over 12000' from Estes Park to Grandby, is subject to blizzards at a moment's notice, any day of the year. It was in a July, August and September (in different years) that I found it closed by a blizzards.
Should you be unlucky to find it closed, CO 7 and CO 72 is another magnificent drive from Estes Park back to I-70.
Lifey