This is one of several spells that I don't try to stick entirely to RAW and homebrew a bit. I don't really have to go over it in session zero because I've been gaming with the same group for years and it is just one of those things we've discussed in the past and they know how I generally rule in these situations are a fine with it.
Generally, petrification in my games mean the creature is turned to stone and it in a kind of suspended animation. There is no consciousness. Not even dreaming. If the petrification is reversed centuries or longer later, the restored creature is restored to the exact mental and physical state at the time it was petrified.
The petrified creature is treated as an object for most cases, except greater restoration.
Except! If a finger, nose, limb, eye, etc. it damaged or broken off, when restored, the restored creature would have comparable damage to its body. Since greater restoration only reverses one effect, multiple casting would be required to restore a petrified creature that was also damaged. Some damage, such has breaking of the head or breaking the body in half would cause instant death as soon as the creature is unpetrified. Better move the statue carefully!
Note, no need for dinosaurs. A single draft horse and pull 8,000 pounds of weight. It would make more sense in dungeon or wilderness terrain to jerry rig a sledge or travois and polymorph someone (or druid wild shape) into a draft horse or, better, a mule (for up to 2000 pounds, less weight, but mules are better adapted for rough terrain).
If you have multiple magic users or want to go slow and burn through lots of spell slots, multiple floating disks could work. But there is danger of the statue dropping an breaking if they are dispelled or you don't time their durations well. At higher levels, animate objects and/or demiplane can make this easier. But at that level one would hope you'd have a divine caster in the party who can cast Greater Restorate.
Failing a test of worthiness imposed by a minor deity.
So that changes things a lot. Would the clerics deity even allow greater restoration in this instance, even if a different deity than the one who cursed the PC? 5e does differentiate much between "divine magic" and character cast spells, something that has come up in my game more with wishes. Of course this is all up to your world building, but I would require that other party members to do something to propitiate the deity, or find favor with an opposing deity (and the ramifications of that), or perhaps allow the greater restoration to work but thaving a geas imposed on the restored PC.