This is another one that all depends on the group you're going with, their ability and how much mileage you think you'll all cover over the weekend. While it can tempting to go to a bigger resort or spend more upgrading the lift pass to access more areas, often, the limited time in resort means you'll likely not get your money's worth.
So best bet is to play it safe. Choose a big enough resort by itself that you'll have plenty to explore. But not too big that you feel like you've missed out on key areas. And by doing this, you'll actually find plenty of options for resorts, that you likely wouldn't consider for a big week-long holiday.