We didn't in the old (prekid) days, but then we just chucked a dustbin liner over the nearest tree and got very drunk for the night, IIRC.
We are thinking of doing 2 weeks of european camping, but we HAVE to reduce our packing to an absolute minimum. 4 x decent sleeping bags would sort that, we have calculated.
What do you all reckon? We already have 2 x 3 season sleeping bags but would need 2 more for the kids.