I was looking into this recently to jog my memory – TCP packets are fragmented based on the path’s minimum MTU (PMTU) and then reassembly of TCP packets occurs. This means in practice TCP packets are limited to ~1500 bytes. See RFC 8900 - IP Fragmentation Considered Fragile for more information if you have some time. That RFC links to another RFC (RFC 4963 - IPv4 Reassembly Errors at High Data Rates) that describes an IPv4 fragmentation attack where a 3rd-party can spoof the 16-bit ID counter in the IP header and cause IP reassembly to fail (when validating the checksum) or pass with corrupted data (randomly passes the checksum which is also 16-bit).
If this is just a typo and you meant Lightning packet then please disregard. I am not sure of the overhead of reassembly of TCP packets, but from what I’ve read fragmentation seems to have some issues. Mistakes my own.