http://bestsnow.net/fam_ski.htm I rate various destinations for spring break.
Summit County is one of the top choices for the altitude. Breck has the most terrain over 11,500 of anywhere and that terrain is great in April though primarily advanced/expert. Primary exposure is east so the easier terrain lower down will melt/freeze. Nearby Copper is heavily north facing and excellent in April. A-Basin is even better though it's smaller and advanced/expert weighted.
Whistler and Alta/Snowbird are excellent choices though they are also advanced/expert weighted. At Whistler it's a more extreme version of Breck: the snow up high preserves very well, but most of it is steep and not groomed. Lower down it can be much sloppier.
For intermediates Mammoth and Mt. Bachelor are the top spring choices along with Summit County. This year Summit County is about average while Mammoth is well above average and Bachelor is having a huge season. So I recommend Mammoth or Mt. Bachelor for spring 2016.
Sorry, just noticed question is for 2017. Nonetheless my recommendation for Mammoth/Bachelor applies anyway. You will usually have good snow all day at Mammoth/Bachelor in April, not just in the AM.