Jim,
in Texas, panhandle excepted, the last week of March is about as late as I would ever consider setting plants most years. And, I generally plant the first or second week of March (subject to long-range forecast). I don't think March 10
is what I would consider "early", especially for your longer DTM varieties, because we have such a short window of time to get good fruit set before it simply gets too hot.
As I'd mentioned to you on DG, I think it pays to have some backup plants and be prepared to protect, though.