I'm pretty sure you'd have a heck of a time getting goodnites to work. They might, but I wouldn't wager money on it. (I know it's not the same diaper, but I picked up the wrong size of Always Discreet's and they've actually been cutting into my legs and hurting me. I'm determined to not waste them, but ouch! I got sm/med and needed large instead. )
Unfortunately this is kind of an un-tapped market. There are pull-on type diapers out there for adults, but they don't have the same aesthetic as Goodnites. No prints or anything. If you don't care about prints, you might try some of the pull-ons for adults. I'm getting a pack of NorthShore GoSupremes to try out because I've heard good things about them.
Goodnites barely even fit someone with a max 28" hips/waist. You might be able to squeeze into them, but even that is typically only up to a 36" waist.
If you really want a pullup I'd recommend you take a look at Northshore go supremes.