Possibly heading to Germany on an unaccompanied 1-year Tour of Duty. I'm NG. Do I get BAH from home or OHA in Germany?

If you are an activated reservist and the military says your family stays home, then your home stateside will get taken care of and you will receive housing in Germany. Probably not OHA but a place to sleep each night.

When I deployed to Iraq I got BAH for where my home of record I assume this would be the same

Double check with personnel sir.