We were there spring break this year. Were told Gondola runs until the resort closes. This year it didn't open until right before Christmas.
If you're trying to come back for lunch, it takes... awhile. Even if Leave the Beav has enough snow to ski you down in the spring, it gets really flat and can take some time, especially if you have kids who don't keep their speed up.
I had to drag my son the last 15 minutes down...
Anyway, getting back up also takes 20-30 minutes. You have to take the Gondola to the Lower BC Express and that takes about 5 minutes, then switch, put on skis and up the Lower BC Express is 7 minutes. Then if you shift to the Upper BC Express, that also takes 7-10 minutes.
We started bringing a ski backpack and just packing up lunch to eat at one of the outlets up mountain. Saves time.