You can, but by time you are halfway through, it's room temperature and getting colder and you have to reheat it again. I don't like stopping in the middle of a meal to heat it up again.
I eat stirfry's at least once a week, and I've never experienced this 'heat loss' problem.
It depends on quantity and how fast or slow you eat. When I get house fried rice and put a large portion on a plate, generally i'm halfway through before the rice is already getting cold.
So then why not just take smaller portions and leave the rest in the container that keeps it warm until you are ready to eat it?