The devasation was immense. Over the following days, news trickled in of hordes of strange abberations. Lantern's light was the only settlement to escape severe damage- The castle of His Iron Grace was overwhelmed almost instantly, and the other cities fared no better. Refugees began to trickle into the city, seeking food, warmth, and a safe place to lay their head. The damage to the city was extensive, but the walls still hold.
The survivors gave strange tales, that those chilled by the breath of the monsters took sick shortly thereafter, and became just as the monsters at their doorstep. Nothing else is consistent between their tales- some claim it is incurable, other do not, some claim it is instant, others do not. Perhaps the codex could tell you more?
It is clear, however, that you will not survive without assistance, additional aid, and a wall of strong men to defend the holdings you control.
To the Northwest is the ancient Burneal Forest, partially overrun with the encroaching Black ice. The forest, and the vast plains to the south, are homes for various nomadic tribes of humanoids, herding mammoth and other megafauna to survive. They have extensive knowledge of the land, as well as decent supplies of food and animal products, and are fearsome warriors.
To the south is the howling hills, as well as several tributaries of the Lake of Unknown Depths. The Dwarven kingdoms trade through these hills, and dwarven engineers could be of much use to you, as well as providing food from their underground farms.
Underground are the Skaven. You have no idea how well disposed they are to you, nor how many of them their are.
You could also head further to the south, and see what you can find. This would entail leaving what's left of Lantern's light and the keep more or less untended.
You have 20 able bodied peasants who volunteered to help protect the Keep. Although they mean well, they are untrained, and would require someone to teach them how to fight.
As you are now level five, you may adjust your total wealth to the level five WBL x 1.5, as normal.
I forsee the next session being more housekeeping than anything. I have a -very bad- mapped version of the keep for you, which is more or less just Grek's picture blown up. Eventually I'll do it in actual tiles.