We actually carry a porta potty in the back of the van when we leave for trips/evacuations. The ladies just climb over the back seat and they actually have semi-privacy.
The ladies in my household are much more enthusiastic about camping when we take the porta potty along with us.
The porta potty has proven to be a great investment from about 20 years ago.
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QMC, USCG (Ret)
The best luck is what you make yourself!