the gov TLD is managed by the US government. It's very rare that you renew anything with ICANN, since you're almost always going at least to the entity that manages a TLD (unless you run a TLD, then I guess there'd be an ICANN fee).
If you have a .com domain, you're renewing with VeriSign, the company that owns the com TLD.
I'll pay for the domain if you find a way to buy a .gov as easily as you can buy a .com. I don't even think a regular citizen can get a .gov unless you incorporate a new city or something like that.
During the government shutdown some TLS certificates expired, so depending how long it goes a domain renewal could get missed because nobody is working or the check bounces.
What if a dept lets theirs lapse and some squatter swoops in and takes it?
We'll start the bidding at $1B USD...