Add note about initial node-pool size for workshops

Document 2i2c-org#2758 (comment)

docs/howto/features/dedicated-nodepool.md

@@ -69,4 +69,13 @@ Some hubs on shared clusters require dedicated nodepools, for a few reasons:
    ```
 
    This tells JupyterHub to place user pods from this hub on the nodepool we had
-   just created!
+   just created!
+
+## Node type and minimum nodepool size considerations
+
+When setting up a dedicated node pool for a hub, particularly a hub supporting
+an *event*, it's important to consider the node type and minimum node size
+used. As there will likely only be minimal number of users until the event
+starts, it's helpful to set the *minimum node pool size* to 0 until at least
+*a week* before the start of the event. A smaller node type is also adviced
+until a week before the event.