preupgrade 10 -> 11 pain: network error

[brian]

I've run preupgrade to download packages, etc. At some point, there was 
a msg stating that there was no room for a boot image (i believe--it was 
/boot/something) but that it would be fine if I have a wired network 
connection. I do, so I continued.

However, upon rebooting, I'm seeing "Waiting for NetworkManager to 
configure eth0 ..." followed by, "There was an error configuring your 
network interface."

The box is, indeed, using a *working* wired ethernet connection (I 
downloaded the packages, after all). I am not using DHCP. The box is on 
an internal LAN with a floppyFW router.

Can anyone tell me ...

1) how to find out *what* this error is?

2) if I cannot resolve the problem, how to make this box bootable into 
F10 again?

3) how to then retry the upgrade process?