Woodweller: "I see possibilities from FL through Newton/Pipestone then into the bay area via the 62 rod portage to the right near the mouth of Pipestone Bay."
Definitely your best bet unless you drive to EP26.
Woodweller: "I'm also curious about the creek between Ella Hall and Good Lakes shown on the map. Is it even navigable in late September?"
I cannot confirm but most likely a bad idea.
Woodweller: "And what happened to Four Mile Portage?"
It is still used and maintained every winter by local mushers. The north end is usually very wet in the summer. Not recommended unless you want to hike through swamp. If you're camping on Fall Lake and have a day to burn, it would make memories.
Woodweller: "Finally, it looks like Wood Lake (ep 26) might provide the most direct access."
Correct. This is the only route I would consider if I was day tripping.