16 degrees of temp loss seems a bit excessive to me, i generally see around 10F on my system which I'm sure is different than yours.
make sure you're mixing and measuring in your initial water accurately, and mixing your grain and water thoroughly as well. If you're just checking the water temp at the top of water that's being heated it will be different than the average temperature of the water.
as a side note, 150 v 145 will only result in a slight (1-1.5%) change in attenuation. So it shouldn't change the profile of the beer drastically.
Oginme's "work around" will work, as long as the issue isn't in your process or inaccurate measurements.
I was hoping you'd post a .bsmx file as that provides all of the data of your setup as well.