OK Yooper, here you go. If you start out with a 150a breaker the smallest wire will be 3/0 al. Use that for the first 80' hop from the end. You drop .8 volts. Then go 4/0, 4/0 4/0 for the next 80 and two 100' hops. That drops 1.2, 1.9v, and 2.2v respectively.
Then use 250MCM for the next two 100' hops dropping 2.1 and 1.7 respectivly. Run 350MCM back to the losd disconnect for another 1.9v.
I think that is 11.8v or just a shade under the 5%.