Does Google show the route as west on US 34 or through Denver. Both routes meet I-70 at either Silverthorne or Denver. US 34 is 12,000' high Trail Ridge Road, which is NOT recommended for motorhomes driven by less than VERY experienced mountain drivers. If the route is through Denver, you need to leave Estes Park very early (like 4:00 am) to beat the rush hour traffic.
Personally, I would recommend going south from Estes on CO 72/119/US 6 to meet I-70 just east of Idaho Springs. That way you avoid both Trail Ridge and Denver.