Since you mentioned redeyes, check carefully. JetBlue's redeye from Denver to JFK (flight 98) recently flew its last flight. The old Frontier redeye is also gone. The only redeye I could recently find from Denver to NYC actually goes to Atlanta with a transfer to LGA arriving around 9:30 AM on Delta. Unlike JetBlue, Delta has the new 40 pound restriction which can be a problem on longer trips if you carry an iron and light tuning gear since most "light" luggage is 12-15 pounds empty and Delta's scales have been known to be off several pounds.
I was counting on taking flight 98 about 10 times this early/late season for ski weekends and bought season passes on that assumption. However, it looks like Denver's mostly inaccessible to NYC folks this year
, so hope for a long season in Vermont this year. It's pretty amazing that the world's financial capital (people with $$) has been cut off from Denver -- the redeyes have always been packed and they could easily have charged more.