Putting A Floor In An Aluminium Boat>putting Would I Be Better Off (heat Wise) Putting An Wood Stove Insert In My Fireplace In The Basement Or 1st Floor?

Would i be better off (heat wise) putting an wood stove insert in my fireplace in the basement or 1st floor? - putting a floor in an aluminium boat>putting

I have 2 fireplaces, which can take more heat in the house on 3 levels by inserting into the basement or 1st I am not affected by heating the basement.