Look, as the apparent blanket hog in my relationship, if you can't defend your blanket it will be taken by the stronger will. Same for side size. My wife sleep persona favours pillows and bed space, my sleep persona demands blanket. it works for us.
I tuck every tightly when I make the bed. At night, I loose things enough to get into it. This way the one who grab the whole blanket is the bed and in the morning we are longer tuck on the sides but still very much at the foot. So the blancket had no chance to escape on one side on the bed as it is stuck by our both weight and the matress. I don't need to tighten it to the foot every day.