/var filled up and can't login locally or remotely

[Tito Mari Francis Escaño]

I got me a 3.8 box as gateway with bash as root's default shell. The
pf logs filled up the /var partition and bash complained about not
being able to load libiconv which I believe is a dependency of bash.
With the failure of loading libiconv, I can't login on the gateway box
and I can't login remotely via SSH. I tried rebooting to single user
but the shell provided (is that ksh or csh?) doesn't seem to change
what root's default shell should be.
Is there a way I can get thru this without replacing the gateway
server and not reinstalling OpenBSD 3.8 from scratch? Thanks!