when the network interface becomes available, the OS sends data immediately, but also all data it has accumulated so far, and only as much data as can fit in one packet, obviously. So suppose you execute write(1 byte), write(1000 bytes), write(1000 bytes), this results in the network packets containing 1 byte, 1400 bytes, 600 bytes. Are you describing a theoretical scenario, or alluding to the fact that this actually happens? Because it does not, at least, not over TCP, boundaries for send or write are not preserved in TCP packets.
Are you drunk?