There is no such think as 1-bit package, quite apparently. The trick is: no matter what you do, you always create some application-layer protocol
]) to conduct your application semantic in your network messages. So you can send 1 byte, but the protocol should state that the only one bit should be considered.
And of course, actual package will be much bigger that that; and you cannot physically send anything without this overhead.
Finally, in practice, it's extremely an bad idea to send tiny bits of data; it's a waste of traffic, when almost all information transmitted is in the package envelope. As to one bit, it does not make any sense at all. However, I understand that it was a question to test your understanding. Not a good one, anyway, because everything boils down to different understanding of the word "send".—SA