It's almost not worth streaming with such a low upload. You could downscale to the 360p or 480p range and try to stream at around 600-700 Kbps, and at such a low resolution probably crank the preset to slow without much impact, but it still won't look that great.
Edit: This also assumes that the game you're streaming and whatever else on your system doesn't need more than the remaining 300 Kbps (~38 KB/s) of bandwidth. I've seen plenty of multiplayer games use more - ArmA 3 and GTAV for example regularly spike to 50+ KB/s - so if that's the case you'd likely experience lag in the game or dropped frames on your stream.