It should be no problem what-so-ever for a trip to longmont, no matter whether you're on the 70 or 80. Once you get west of Longmont, is where the serious grades start. Snow will be a non-issue in June.
2016 Ford F350 Turbo Diesel SRW 4x4
2017 Grand Design Reflection 297RSTS
2013 Ford F350 Turbo Diesel SRW 4x4 (Destroyed by fire - 8/29/16)
2014 Grand Design Reflection 337RLS (Destroyed by fire - 8/29/16)