The Bal en Blanc organizers have been busy, and they have scheduled parties in the main clubs of the city. You can always visit their site for more info, and here you will find the ones I think would be interesting to attend, and some might not be organized by the Bal en Blanc at all.
Personally, sorry if you are expecting to read a review, but for the first time in years, I won't be attending the Bal en Blanc main event. nevertheless, I shall be at Stereo on Friday for Sander Kleinenberg, I'm probably checking out Tracy at Parking on Saturday night, have not decided if I'm doing Erick Morillo at Stereo on Sunday, and I'm almost sure I shall be at Parking for Victor Calderone on Monday night.
The weather is going to be absolute beautiful in Montreal, and you should enjoy it as much as you can. Partying or not partying, there is something for everyone, welcome if you are a visitor to the city, and be nice if you are a local, and dress in white if you are going to the main event, and Happy Easter.