Before DS was in real school, we went around that week several years in a row 2013-2016. Really loved that time as there’s just a ‘touch’ of a breather between the Presdent’s Day / Princess Half Marathon period and when spring break starts to kick in. Obviously things can feel different every year with changes in the US economy, global economy, new school calendars, etc - but it worked well for us.
Also you’re generally in a warming trend by that point, weather wise.
One thing to watch in 2019 - Mardi Gras is much later than it has been the last few years. It’s Tuesday, 3/5/19. The whole state of LA is off and it’s historically a larger crowd week, relatively speaking. Sounds like this will be just after your trip.
I don’t think Princess Half dates are out yet, but it’ll probably be 2/22-2/24ish. I wouldn’t plan around this, just something to watch out for that Sunday AM (traffic/congestion primarily around MK and Epcot).
Happy planning!