OK, time for a longer trip report. After reading this thread, we were mostly choosing between Utah and Colorado. Another option was Vermont, but when I saw how much our kids were skiing at Greek Peak this season (all Saturdays and Sundays, usually from before 9 in the morning to around 3 or 4 in the afternoon, even in the rain), I wanted to show them how "real mountains" look like and was confident they would enjoy skiing a big mountain.
Decided to go to Colorado, and specifically stay in Fraser, for a couple of reasons. First, there is a direct flight from Syracuse to Denver, which is a lot more convenient for us than driving to EWR or JFK. Second, I figured out that Winter Park has snowcat tours, and, knowing how much our boys love all types of machines, I knew it would be a hit. Another big factor in favor of Winter Park was that it is off the beaten path a little bit, and also it has very convenient parking (right next to the lift at the Mary Jane base). Copper is right on the I-70, and one has to take a shuttle from the parking lot to the lifts.
Here are the boys in the cockpit of United's Airbus (I'm a huge aviation fan, doing my PPL now, and they are getting more interested in aviation, too):
Here are the pictures from the snowcat tour (with hot chocolate and smores):
We had 8 days in Colorado. I skied all 8 days; the kids skied 6 (2, then rest for a day, then 2 more, then rest, then 2 more). In total, we did 7 days at Winter Park and 1 day at Copper. Here are the photos on the hill:
Here is the Berthoud pass on the way back from Copper:
And here is the video of the boys skiing:
We absolutely loved Winter Park. It has an interesting layout (we didn't really ski any green runs, but there are lots of great blue runs all over the mountain). Really enjoyed Cranmer and the race course set on it; skied the trees off the Olympia lift; liked the Mary Jane and Sleeper runs; skied the runs off the Wild Spur Express; and the list goes on. We liked Copper, too, but found the signage on the mountain to be more confusing than at WP.
The kids made a huge progress over these 6 days. The younger one learned to do hockey stops and to sideslip without any input from me. They also skied trees for the first time on their life. They got a bit sick on the second day in Colorado (probably because of the elevation), but were feeling fine after a day of rest.
Overall, it was an amazing trip. Yes, traveling with 3 kids (a 5-month old in addition to the older boys) can be challenging, but skiing in the West is on another level, especially considering the weather and snow conditions we had this season in the East. The boys already asked me if we are going to get Ikon passes for next season and go somewhere West again, and I think I know what the answer will be