Unfortunately, the only way to make sure you're well connected now is to keep enough open, but this is rather wasteful.

In Gnucleus you can use the tools->statistics->bandwidth tab to see how much traffic a connection is using (more traffic means likely more hosts too).

I'd like to see some sort of minimum bandwidth setting to take the place of the "friends" one. Even better would be something that looked at the number of search results and other "useful" packets a node returns. A higher result to query ratio might be an even better judge of how "good" a node is than bandwidth or connected hosts.