He is technically Commander in Chief and does not need to consult Congress.
However, he is blurring the lines in general, since he disregards Congress on things like appointments where he is obliged to seek counsel.
I think you are wrong on that. He has authority to act for 90 days,, following that, he needs congressional approval.
I believe we went well beyond that in Libya.
The initial authorization for GW was never repealed.