North Padre Island is mostly National Seashore and pretty wild. The
Laguna Madre, the water between the barrier island and the mainland is
okay for canoing and kayaking but check the marine forecasts before
hand. I do know that there are alligators in Texas, but I don't believe
it's anything like Florida.

The closest civilization would be in the northern part of the area near
Palacios.

South Padre Island is pretty developed. There are two county parks where
you can put your RV, but you will need reservations. They fill up
quickly. The northern one is the more remote one but development is
encroaching there, too.  There is also a KOA at the south end of the
island. Over-priced and tight.

The Laguna Madre can also be canoed  or kayaked but it's a larger body
of water and you most definitely need to check the marine forecasts.
Swells can get very high.

Some of the rivers that empty into the Laguna Madre are nice to canoe.

It's been my experience that the weather barrier between the
semi-tropical Lower Rio Grande Valley is around Kingsville. That would
make Palacios above the too cold for Janet line.

The Sand Dollar RV park in Fulton, TX (near Rockport) is fairly handy to
both Padre Island National Seashore and the ample small boat waters in
the Rockport area.

I've encountered horrid mosquitos in several areas, including Sea Rim,
near Beaumont, but there is not a mosquito problem at the Sand Dollar,
not much in the Rockport area, in general.

    -Raf