Only thing one has to keep in mind are any of the usual GB limits attached to such a deal.
Worst-case, the System is a vanilla Windows 10 Installation and can suck up xx GB of bandwidth for undesired auto-updates. That's something to keep in mind when considering such a deal.
If you are using a mobile connection via wifi, you can set it as a metered connection via the wifi options menu and it will stop the automatic download of updates.
As for the game, I have two ways of connecting and they're both 4G. A home line with no data cap but limited to 20/30 Mb down and 3-5 up, and my phone one with a 10 GB monthly cap but reaching up to 80-90 down and 15-20 up. Always played perfectly with both, even in CQC and even on a moderately high ping (usually in the 40-50 ms on nearest Speedtest servers).
@777Driver ED seems rather tolerant on network requirements, I think you'll do fine on anything better than 5-6 Mb down and under 100 ms ping.
A note on Steam: it definitely throttles certain connections, usually on a provider basis. My home provider gets capped at a max 600 KB/s download, I need to login to Steam via VPN to let it download at the average 2-2.5 MB/s it should actually do.
(And no, I don't rage-uninstall games, or I'll pay the consequences dearly

)