I think that it is wise to draw on the experiences of others but in the end there is no substitute for firsthand experience. "How many miles have y'all ridden in one day?" My question to you is how many miles have YOU ridden in one day?
There is plenty of time between now and March for you to find out what is a comfortable distance for you and your bike. I've found that most people can do 300 miles a day without too much of a problem. You can plan a few rides that make a loop of 250-350 miles (or whatever) around the area where you live without ever getting very far from home. That way you can take a "shortcut" home if at some point you feel the need to "just get home" for whatever reason. It wouldn't be a bad idea to do this several days in a row if possible because you may find that you can comfortably do more miles on the first day than on following days.
I had about the same bike as you (mine was a 2000) and put way over 50,000 miles on it. My experience with that bike and a stock seat was that stopping about every 100 miles or so for gas and a little walking around worked best for me. I could keep that up all day and if the day was long enough I could easily cover 500 to 600 miles without becoming too fatigued. In March there are about 12 hours of daylight each day but you have to figure in the time spent stopped for gas, food, rest, etc. As a general rule I avoid riding in the dark for most of the year but I would make exceptions to that in the heat of the Texas summer. Your mileage may vary but my 1100 Spirit wouldn't go much past 125 miles before going on reserve and I liked to stop before I reached that point because I don't like going on reserve.
As far as your trip is concerned you could take I-30 to Little Rock then US-67 to Walnut Ridge. This would be close to 500 miles. It would be a long day but you could do it easily if you don't mind sticking to the interstate. But that route would take you to the south of the best roads in the State, there are much better routes if you are willing to take a couple of days to get there.
When I lived in the DFW area the Ozarks became my favorite motorcycle vacation destination. So much so that when it came time to retire I decided to relocate here more for the roads than anything else. It helps immensely to have a loving and understanding wife! We bought the house in July 2012 but didn't make the move until September 2013. During that period I made the trip between Ft .Worth and Flippin every chance I got just to check on the place. I took advantage of every three-day weekend but I also did it on a number of two-day weekends. I would leave Ft Worth (Arlington, actually) early on Saturday morning and arrive in Flippin late in the afternoon. After a good nights sleep I would return to DFW on Sunday. On the map it should have been 1,000 miles but it usually managed to work out to more than 1,200. If you know where Flippin is then I don't need to tell you what the roads are like around here. So, I'm very familiar with the roads and would be happy to make some suggestions if you would like. Maybe we could meet up for a ride, I know a couple of good BBQ joints.