Personally, there is no way I would leave it unlocked. There are way too many things that could happen with the door unlocked. Vandals, thieves, curious people, etc. We always lock our motorhome and there is a sign in the door and opposite side window that says 3 cats are inside. I think it is just way too likely that your pet(s) will be stolen and/or let free either intentionally or accidentally. If you decide to not lock it please don't post it here, so I don't have to feel sad about it.
Ken
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