So much juicy info in the Public Interest Statement that T-Mobile and Sprint put together for the FCC. Page 23 and 24 have some maps that show the projected extent of 5G coverage on both networks in 2024 if they were to go at it alone. Beware, the document is over 600 pages long so if anyone has free time and wants to go through the whole thing, please do!
https://ecfsapi.fcc.gov/file/10618281006240/Public Interest Statement and Appendices A-J (Public Redacted) .pdf
I'll keep editing as I find more cool stuff.
Edits: I'm still reading but something to note is that on their own, it is expected that by 2021, Sprint will cover more POP's in high-speed 5G than T-Mobile. So while T-Mobile would have greater overall coverage by a long shot, Sprint would be capable of providing 153 Million POPs with speeds greater than 150Mbps compared to only 10 Million from T-Mobile.