I need help with the best method for DH and DSs to do Steamboat Springs for spring break. Count me out...I don't do cold. I am annoyed b/c this is messing up my stash for Hawaii next year, but Hawaii was for DH and if he wants to postpone it to hang out in the snow, so be it. DD3 and I will go to Disney instead.
I booked a Hampton on points, so hotel is taken care of. Unfortunately the Sheraton that is ski-in/out is booked full for the dates.
I will book SW flights probably....just waiting for them to open late next month.
I need help covering the cost of lift tickets/equiptment. There is a buy an adult, get a kid free deal...so total is about $1500. The Steamboat website has a banner that says pay with MRs, but when I click it, nothing happens. He isn't getting the URs...those are mine for disney.

What should I open to help mitigate the cost of lift tickets? He is 2/24 with one falling off next month. He is already drinking from the CIPpy cup. I need another idea...like the arrival+ that is no longer an option.
We skied at Steamboat for a number of years, but haven't for the last two seasons because DD aged out of the free ticket, and the local ski pass jumped in price astronomically. We used to get a pass for $1000 for all 3 of us, now that pass for 3 would cost $2900.

Steamboat is my favorite (relatively easy to get to) ski area. Just a quick question - are they beginners? Will they be taking lessons? The advantage that the lessons provide (in addition to instruction) are jumping the lift lines so that they are not waiting in line 45 minutes just to ride the lift FWIW.
I'm not surprised that Sheraton is sold out. It has the best location for skiing Steamboat.
The Ikon base ski pass allows 5 days at Steamboat, so depending on how long they're staying at Steamboat, it might be just right for spring break. $749 for adult ticket, $559 young adult 13-22, $359 child 5-12.
https://www.ikonpass.com/en/shop-passes/ikon-base-pass-2019-2020 That's a little bit less than the $1500 you're looking at.
We don't rent since we have our own equipment, but Christy Sports at the base of the mountain would be the most convenient. Plus IIRC they can store your skis overnight (for a fee) so that you don't have to lug them back and forth from the hotel (skis/snowboards are heavy and awkward especially when you're walking in ski boots). It takes a long time to get fitted for boots and skis, so if I were renting I would look at getting them the afternoon before I plan to ski so that the morning isn't eaten up waiting to get equipment (I would expect that alone to take 2 hours for 2 people during spring break). Another idea would be to rent equipment on the way to Steamboat (Golden, Idaho Springs) where it might be less expensive, but they would need a car big enough to hold the skis.
Know that it is a 4+ hour drive from Denver to Steamboat, and probably longer in the winter - March is our snowiest month* - and (I assume your DH would be driving to the ski area?) can be treacherous. I-70 has AWFUL traffic during ski season, especially on weekends, and I've driven on Highway 9 going 10 mph and wanting to cry since I couldn't see the road in front of me due to a snowstorm. I've had it take 8 hours in the
summer coming back from Steamboat (heavy traffic), so my advice would be to plan for long transit times, and have emergency supplies in the vehicle.

And sometimes, the drive has been perfectly fine. Hopefully it is not a horrible drive for them, but it has the potential to be.
I may sound like Debbie Downer, but I've lived here long enough to have experienced the pitfalls of Colorado ski resort vacations. Don't get me wrong, they can be a lot of fun, but they take a lot of prep. Hawaii is much easier.
As for CCs, since he's already getting CIPs, & without being targeted for higher offers, the non-Chase cards with $500+ SUBs that I'd suggest are BoA Premium Rewards and Cap1 Venture. Of those, I'd go with the BoAPR due to ease of redemption and airline agnostic travel credits. Get a BoA bank bonus too (and first so that you have a "relationship" with BoA).
*As a side note: Steamboat got 2 feet of snow on June 21 this year, the first day of summer. That was unusual.