I've driven 2 days, but those are for those week long trips I mentioned. I'll usually book a KOA about 1/2 way to those as well. Like, for the Pigeon Forge trip, I booked into a KOA in Cincinnati for a night on the way there, and on the way back. But those trips I'm not going there just for the KOA. I'm going there for the tourist trap offerings, and making use of a KOA as my choice of campground while there.
Looking at the KOA map, looks like there's a handful of parks in the maritimes, 1 in NFLD, 2 in NS, 1 in NB and 3 in PEI. How distant are those from you? I remember several years ago I was on vacation in Halifax (pre camping days) and I was able to drive to Charlottetown PEI and back to Halifax in a day. It was a long day, and we didn't have long in Charlottetown, but surely you could make most of them (except maybe NFLD) in say, a day's drive since you'd only be heading in one direction. It looks like the kind of distance we'd probably do for an extended long weekend (like take the friday off for the drive there, spend Fri, Sat, Sun, drive home on a holiday Monday.)
Oh, and I realize we're going completely off topic, so to 'kind of' bring it back on topic, of course you wouldn't be able to do any of those trips other than the one in your home province until they open the borders between the provinces. There, that's back on topic right?