Leaky nighttime pull-ups Anyone know of a solution?

I get the Huggies Learning Designs for my son-you can adjust the side tabs so they are tighter. I've used my son's pull ups on my daughter, who is smaller, and she stopped having issues when I tightened the tabs. She was actually ok in a 4T/5T when I usually buy the 2T/3T for her. You can't do that with the Pampers, but for me, the Pampers leak less if I get them smaller (I use a 2T when in other Pull-Ups she would be a 3T)