The situation is different at each of those three.
Owls Head: To clarify, I assume you mean the Owls Head in Cascade Pass. There are at least three other "Owls Heads" in the ADK. For the popular Owls Head in Cascade Pass, that trail is closed on weekends, so you probably will not be able to hike that.
Mount Jo: Yes, crowded, limited parking. The parking limit for Mount Jo is a relatively "hard" limit. The roadside leading to the ADK Club lots is posted "No Parking." So if the lots are full, then you would have to park a fairly long way (couple miles) away.
Indian Head: Also crowded, limited parking, but this is a "soft" limit, at least for now. If the AMR lots are full (and they almost certainly will be), people park along the shoulder of Route 73, sometimes for a long way down the road. So it's a bit longer walk, but at least for now the highway shoulders are not posted "No Parking" so your walk would not be extended as much as it would in the Mount Jo case. (There is talk from DEC in the latest plans about eliminating the roadside parking. If they pursue this, there will be a catastrophe; but it has not happened yet. Just be careful to watch for signs, etc.. DEC plans to "pilot" some of their more idiotic ideas on Columbus Day Weekend.)