Camping in the rain

Just a few weeks ago, on Memorial Day weekend I went camping in Northern Utah.  Red Fleet Reservoir State Park, near Vernal, to be exact.  It is a very beautiful place, lots of rock features and a large lake to escape to when the weather gets hot.  There are also remnants of dinosaurs.  In the park there are a few featured fossils, most notably large dinosaur footprints in the rock at the lake shore.  All in all a great place to take the family for some nice camping and activity filled fun.
This trip included my own family and the family of my sister in-law.  In total there were five children.  We thought we were in for a great weekend.  We had planned a trip for Yellowstone but temperatures were way too low for comfortable camping.  Then we were going to try Southern Idaho, weather didn't look good there either.  The Vernal area showed promise of high temps and clear skies.  Much to our chagrin the weather turned sour on the first night.  Rain started falling as we finished our s'mores and didn't let up until we had our trucks packed the next morning.  The wind was horrible, almost collapsing our tents.  We couldn't stay another night, things were just not fun any more.
You might be thinking, "but Geoff you always claim to be so hard core and a know how type of guy, why did you pack up and leave".  Well, to answer that, things change a little when you are camping with small children that have to be cooped up in a tent because of bad weather.

The thing is there were many people with RVs and trailers that were able to hang out and enjoy the sun when it poked through.  They didn't mind rain and wind because they were sheltered away in their houses on wheels.  However I have always felt camping in an RV or trailer was a little too extreme, a little wimpy.  Those people all got to stay out for the weekend though.  Should I be changing my mind about camping in a mobile house?  Honestly this was a internal dilemma I was having, not only for myself but for my children.  I don't want to have to go home early and have them miss out on the outdoor experiences they already love so much.
After much internal thought and lots of online searching I found the answer to my problem.  RVs and trailers are too extreme.  I don't want a shower and toilet to use in the outdoors.  I don't need mini-blinds to hide the sun away.  I don't need lush carpets and leather bench seats to relax on.  So what is this answer you ask?  It is the conversion of a cargo trailer into a camper.  Just enough protection from elements and just primitive enough to feel like you are still camping  (also much much cheaper than buying even a pop-up trailer).  This site has the best pictures to describe what I am talking about.
Benefits of this style of homemade camper: cheaper than the pre-made type, can use for regular hauling, customizable, changeable, weather proof, light weight (uses less gas to pull a lighter trailer), just large enough to throw the family inside when the weather turns bad, you don't have to use it if the weather is nice (people will think you only used it to pull your gear), no set up for toilets and power because you are doing your best to be a normal camper.
My wife and I have already decided to go this route when the $ is available.  We are a family that loves being outside and we want to stay outside even when the weather wants to force us in.