cloud saved games

Hi I am trying to sort this out for my grandson, not doing well.

he has box 360 and xbox 1s, the box 1s has and external drive connected with plenty of space on both hard drives internal and external.

he played GTA5 on 360 and it clearly asks as to where you want to save game data, hard drive or cloud.

using same handle and sign in details box 1s via system , storage, only shows external and internal drives no cloud. ( he has gold membership)

on his home screen xbox1 on the list of menu under gold, the circle continues to turn as if its looking for something or can't sign in.

what he wants to do is use data from 360 game GTA5 and update his xbox1 GTA5 data so his progress is matched. ?

I am looking on xbox1 for Cloud, to use the saved 360 data to xbox1s, am I off the track here, is this possible, or just bite bullet and start over on xbox1s

any help great .

:)