My personal preference going north from Albuquerque is US 285, not I-25. You will cross Poncha Pass, Trout Creek Pass, and Kenosha Pass, all easy with an RV. In Denver, take C-470 to I-70, to I-76, to I-25, which takes you around the northwest side of the city. Dakota Ridge RV Park is just off C-470, if you need an overnight stop. Or you could stay at Bear Creek Lake Park (look up "City of Lakewood Parks and Rec"), which is right at the interchange of US 285 and C-470. Then you would be close enough to have dinner at the Morrison Inn (Mexican) or The Fort (for buffalo or elk steak).