Am Fear..you have the right idea about a tent.there are small one person tents that are like that bug shelter but have a rain fly and would be a much better shelter than a tarp or make-do shelter from a poncho.
many years ago i went on canoe trips using my canoe and a tarp for a shelter.the canoe made a secure water proof roof but taking it down and putting it up in a different way at each camp site was a lot of work.a self standing tent was a few pegs and a couple poles and went up fast in bad weather anyplace.
i think folks are looking for to many clever work-arounds when it come to a basic shelter when a small tent will fit the bill.
i have a old one from the "orange camping gear era" i'll dig it out for a photo.