[b1mcp]

A couple of points

1. 7-8 degrees is not cold. In the context of the tensioner adjustment, the "cold" position is for -20 degrees C. Middle is +20 degrees C, Hot is +50 degrees C. So you're probably closer to ideal than you think.
   
   
2. The tensioner is absolutely fine. Just slacken off and go through the tensioning procedure again if you think it's necessary.