If anything could get republicans to impeach and remove Trump, it would be an invasion of another NATO country that resulted severe economic consequences for numerous multibillion dollar US companies (Apple, Amazon, Tesla, McDonalds), throwing the US and likely the world into a deep economic depression.
It would also result in corporate donations to republicans evaporating for the foreseeable future.
Nobody except a few crazed zealots wants to see the US invade Greenland.
The staging of such an invasion would be telegraphed widely before it was launched (as was the case with Venezuela), with troop and ship movements easily tracked. This would likely give congress time to pass a war powers resolution (NATO is way different from Venezuela, so no one should compare them), and send an emissary (I nominate Lindsey Graham!) to have a Goldwater-Nixon chat with Trump about the consequences he faces if he gives the order to invade.
I think it why we have seen him desperately seeking the least embarrassing off ramp, pivoting to threatening NATO members with tariff hikes if they dont support his plans- its stage 1 of a typical TACO reversal.