Home Depot sells a couple of types of foam insulation, one for regular spaces, and one for around windows. The Windows one is meant to fill a space and not exert pressure to break a pane of glass. I think the window stuff is pink (foam). I would suggest getting some of that and filling the holes (around the propane line) so that the line isn't squashed. But enough to keep voles out.

Back to the salt mines tomorrow. The break has been nice - I did a lot, but not as much as I hoped. As is ever the case.