I would just fly to Denver and stay nimble until you get closer to the trip.
Crowds and traffic should be a non-issue.
It is hard to predict what will happen with the storm cycle and snow conditions as a lot can happen in 2-3 weeks time. You could arrive in the middle of a good snow-cycle. You could have warm/spring conditions. It could be really, really warm that week..who knows.
Summit County preserves the snow best. Aspen could be a good choice
Nice part about coming during that time in April is the lack of people. I do think that Easter weekend will be somewhat busier than a typical April weekend, but will be nowhere near a typical winter weekend in Summit County. I think there will be an uptick in out-of-state/destination skiers at Easter versus a typical April weekend, but I doubt the Front Range/Denver skiers will show up anymore than normal since they've gotten their fill and will be more interested in warmer weather/spring activities down in the Front Range.
Plus, with the longer daylight hours and probability of good road conditions, driving over to Aspen should not be too difficult. You could easily ski Summit County, and drive over to Aspen after a day of skiing and make the drive in all daylight.