A more like response by Reagan would be to place a dozen squadrons of US Aircraft in Poland and Romania, backed by 4 armored divisions at full readiness.
Hell, that's a fitting response now.
But NOTHING in Ukraine.
Reagan would definitely have the CIA active, and he would have started fighting Putin from the first day he took office, and even at this late stage he would be offering effective resistance and making Russia pay a price, regardless of how you want to falsely portray him.
Reagan would be operating, not just making a show.