I tried to head up to Warbler's on a trip last July, although to be fair I wasn't trying that hard. I was camped on the east end of Big Trout and figured I'd run up there to take a look. I didn't find a way through or even an obvious route to take by the time I was around here:



Even to get that far I was poling my (empty) kayak through very shallow water. And since I didn't particularly feel like wading in peat bog, I turned around. I know that's not much help. Most likely there was a route I just didn't spend the time to find, but I'm sure May water levels will make a big difference. 

 

There are lots of good sites on Big Trout so you shouldn't have any problems finding something you like. On the east end of the lake, the far east island site is supposed to be nice (it's shown in the AA PCI index if you want pics). Last summer I stayed on the westward facing point site southwest of the island site. Nice rock to sit on and enjoy the view, deep water for diving (probably good to sit and fish from too). Only problem was finding a flat place to set up my tent. I managed, but I think it was the only reasonably flat spot anywhere on that site, so if you're bringing friends you'll want to look elsewhere! 

I've stayed on five or six different sites on Big Trout, and they were all at least good, if not great.