Yes, Ronald Reagan could lead the present-day GOP, because he was a leader. The GOP leadership would not control him; rather, he would control them. Regan had a wit and a charm that even his adversaries thought was amusing. He could tell a good joke. His jokes helped crumble the USSR. He could handle the GOP.
To the present-day GOP, Ronald Reagan is the most perfect human being that has ever existed and any statement is automatically correct if he said it. They would be under his thumb the moment he stepped forward, and he would never be challenged on a single thing he said or action he took.
If you look at the comments of Ronald Reagan versus what contemporary Republicans say on a daily basis, the answer is a clear no. He would be considered a spineless tax and spend liberal. Those people honor him as a hero (which he wasn't), when in reality they would laugh him out at the primary elections today.
Reagan was strictly a puppet for his financial overlords. Anyone can watch the footage of his old conferences and see dozens of corrupts CEOs and brokers who took advantage of the poor in America. These friends of his combined with decaying mind made him a poor leader in the 80's and he would only be worse off now.
Many unfortunate trends we are experiencing today, like growing
income-inequality and fall-out of the failed trickle down concept, were
started during his presidency. Reagan set into motion most of the destructive practices that have led to our current situation. Even so, I think even he would be mortified at the extremes to which his "innovations" were taken