Some excellent suggestions here. I think it makes a lot of sense to do your off-road riding on the way to Florida.
And as you can imagine, the CDR in March would be snowed in. I really like kokuban's suggestion of heading down to Death Valley and parking the truck in say Panamint Springs or Furnace creek and riding your DR over to Titus Canyon and some of the other cool DV off road stuff. And then heading over to Big Bend National Park in Tejas for some more off road riding.
It would save time and money having to park and fly back.
Just some thoughts.