Is this Itinerary Good for a 5-day Colorado Trip? (I can extend to 7 days if necessary only.)

I am travelling with my family (3 people total), and I would like to visit all national parks in Colorado. I have already visited Rocky Mountains National Park but I might revisit if I have time. Can you please see if my itinerary is good? We will have a rental car. The hotels and flights are not booked but if you have any recommendations or changes please let me know.

Flights: American DFW --> DEN lands at 8am, and the return flight leaves at 6:10pm. It total the price for the flight tickets is $620.
Rental Car: (Undecided yet but the ballpark is around $250.)
Day 1: We drive from Denver to Great Sand Dunes early in the morning, and spend some time at that national park. We will watch the sunset and stay in Alamosa, the best hotel I've seen is the Fairfield Inn Alamosa. I'm still debating whether to pick the standard 2 Queen for $273 for 1 night or the 1 king bed studio for $297. I'm mainly leaning to the studio. Has anyone stayed at Fairfield Alamosa? This is the most concerning out of four hotels I'm booking since the rooms don't look so great.
Day 2: We drive to Black Canyon of the Gunnison National Park early in the morning and spend the day there. In the evening, we drive to Montrose and stay at the Fairfield Inn Montrose. We will stay in a 1 King Bed Suite for $307.
Day 3: We drive to Telluride and explore the city. We do the gondola ride, explore the city, and just take in the views. Anyone have any recommendations for things for things to do in Telluride? As for the hotel this is where things get really expensive, lot of the hotels are sold out anyway. I'm looking for a lovely, luxury hotel but not too expensive. So far I'm fixed on the Madeline Hotel Telluride for $945, which I guess is good for Telluride but for a Denver trip I feel like paying that price for 1 night which is more than the flight tickets is insane. Is there any other good hotels that you might recommend or have you had some great experiences at the Madeline?
Day 4: Here we explore Telluride a bit more further in the morning and then drive to Mesa Verde National Park, where we finish off our final national park. Then we drive six hours toward Denver which I've heard is a very scenic route. This is where I really need your help deciding a hotel, should I stay at Four Seasons, Ritz-Carlton, or a different hotel? Four Seasons is $460 for 1 night and Ritz-Carlton is $350, Ritz-Carlton is significantly cheaper but I am wondering which one of these has a more "luxe" experience. I am a Marriott member so staying at the Ritz can earn me points but I never really stayed a Four Seasons so I want to experience that too. Which of these hotels should I choose?
Day 5: Explore Denver, maybe visit Rocky Mountains National Park if we have time. Catch the 6:10PM flight back to DFW.

Is this a good itinerary? Let me know if there are any changes, and thank you for those who read and answer my questions thoroughly, I really appreciate you taking your time out of your day to help me.