Unfortunately no
I think it's very hard to calculate the size for the fragments of an m2ts file. The complete size of the m2ts file is known, what what space is needed to the 45 fragments? You have the in-out time to calculate the length of the fragment, but you never know the size of the fragment before reading it.EDIT: While MKVToolNix was displaying the wrong size and gave a time estimate that was wayy to long