Hey Ben,
I ended up doing mine for as much noise containment as possible, as I live in Arizona. So, while you have the brutal winters I have the brutal summers. If I stay in this house another summer I will be seriously considering a mini-split A/C unit, but so far I have sucked it up every summer and still been out there like any other day (time allowed).
FYI, my garage walls were already insulated, only did the ceiling, but for the interior house walls we cut 4" holes between all of the studs and then blew it in and recovered/textured/painted after. Was a fairly quick process…however this was before the kiddos came lol
-Mike