I think Earth would be a naked eye object from Uranus or Neptune, IF you could observe it favourably at maximum elongation, just after sunset or before sunrise (to get away from the Sun's glare).
According to SkySafari, if I change my viewing position to Neptune, and choose Earth as my target, Earth is a Mag +3.6 object. From Uranus, we're a Mag +2.7. Even the Moon should be resolvable as a separate object with a small telescope or binoculars.
You wouldn't see Earth as anything more than a pin-point though, so forget trying to watch for weather events - the Earth is less than 1 arc-second across from that range.
And if you think viewing Mercury is tricky, you should try spotting the Earth from Neptune - we never get further than about 1 1/2 degrees from the Sun!
Guessing my 8" Dob might not cut the mustard! 
