Few schools allow transfers mid-semester, but this will all depend on the destination school. DS declined admission at one school that told him that should he later wish to transfer, he could. I also know kids who were heavily solicited by schools as recruits and subsequently tried to transfer to them without success.
With all that said, it’s awfully early in the year to have concluded that the current school was the wrong choice. Unless there is some very grave issue (i.e., medical issue requiring regular access to a specific type of facility/staff), I would do everything possible to make the current situation work. If it’s still wrong in spring, pursue the transfer.