C7000v2 Firmware Update

> I'd like to update the firmware on my C7000v2 Cable modem/wifi
> rounter. [...]

   Why?

> [...] Everything here says firmware updates must be pushed from my
> ISP. [...]

   So far as I know, everything everyplace agrees.

      https://kb.netgear.com/000036375

> The nighthawk app doesn't allow me to logon (the ever common timeout
> issue...)

   I'd stick with a web browser.  Less Netgear software involved that
way.

> Appreciate any thoughts or help.

   Thoughts are easier than actual help in this case.