Low Melting Point solder paste reflow profile adviced
The main problem with this low temperature will be activating the flux in the solder paste to make a good joint, it's not just the melting point of the solder. 

You may hope that the lower temperature gives you more leeway for the ramp up. It's not just being gentle with the packages, the paste has to dry out as well.

So you need to look out the specification for the paste. If you don't have the spec, then do several experiments.