What you want to do is possible, but not necessarily easy.
1. You will be sailing to a schedule, and that often causes problems when the weather
doesn't cooperate. It sometimes forces you to sail in bad weather
where you or your boat can get hurt.
2. Cyclone season will be a challenge. You will probably need to carry insurance
that covers your boat if it stays in cyclone alley.
3. There may be restrictions how long you can leave your boat in different locations. Some countries only care how long you are there, and others are more concerned about how long the boat is there.
If I was thinking about doing what you want to do, I would consider hauling the boat out at each destination
if it was cyclone season. If it wasn't cyclone season, I would have it in a secure marina if that was possible.
Your plan is also heavily dependent on the weather. Some years the South Pacific
weather cooperates and is nothing but good. Your plan would work well during one of those years. But if it's a bad year weatherwise, you could face major challenges.