Should be able to Sherry ($400.00 spot, and that will go DOWN after March 1st and again after April 1st.)
Look at all those campground books and look at the ratings. The higher the ratings, in a lot of cases, the higher the rent!
There have been reports of those ratings being off, as in we don't always agree with the ratings! But, generally speaking they are a pretty good indicator. We find most are pretty close.
When you are 1 to 2 days out, say, San Antonio area, coming down I 35, start calling the parks you have chosen. You can call at lunch, you can call while Hubby is driving, try to call before 5 PM. You don't have to wait till you are in Mission.
Besides, by the time you get to Mission, from the sounds of your trip, you are gonna be old pros at this!
Remember the RGV goes from Brownsville to the south, Padre Island to the East, and way past Mission to the west, and at least to Edinburg to the north. That covers what, over 90 miles from Brownsville to Mission, it is a large area.
Here is another way to look at it, would you travel via car and go into a resorty type area without a reservation at the local Baymont or Hyatt?? If that is the way you travel, then going via RV without reservations will be bout the same to you.
And congrats on the retirement!