I prefer Method #1.
That's the method I played by when I was still playing DP OU (I almost exclusively played on WiFi). I distinctly remember a few cases where I had to weigh the risk of breaking sleep clause (and losing) or not against a sleeping Blissey. Natural Cure = Win. Serene Grace = Lose. In some of those cases, the risk was well worth it because I would have lost for sure if I didn't attempt the sleep. In those cases, Method #2 would cause me to lose.
#3 is okay too if you can find all the exception cases.