If you have a physical golem then there's no reason why it couldn't pass through a threshold, however you and your ability to make it move will still be outside so in theory it becomes a pile of rocks... or whatever you made it out of.
Oh, hi, Mr. Warden! How are you this fine day? My, what a shiny sword you have there...
Either way, the end result is that thresholds and wards suck more for you.
Nothing beats molotav cocktails through a window... screw your threshold, buddy!