Your best bet for real mid-winter conditions are probably Colorado and Mammoth (in terms of odds... but who knows really and much of the west should be good). I've been to both around that time of year, or later, and had good winter conditions. Sometimes there can be early spring and freeze/thaw cycles a bit, but so far this has been a great season. Later in April you would be more likely to get slushy conditions (though I've had nice late April powder days a couple of times too.) Basically, through April, the chance of real spring skiing climbs, so early in the month it's likely to still be good.
The places in Colorado that are high and preferred in that case would be Copper, Breckenridge, Keystone, A-Basin, Loveland, and Winter Park. A-Basin, Copper, and Winter Park are Ikon, Breck and Keystone are Epic, and Loveland is independent. Are there any other specific things you're looking for?