You are in the wrong forum. This is the test forum. Click on the "Find Your Roll Call" link at the top left of this page. Look for the Roll Call for your Cruise line/Ship/Sailing Date.
It's never a good idea to fly in the day of your cruise. Sometimes things happen and that's your only choice but if possible fly in at least one day early.
For lots of info on Miami hotels check out the Florida Departures Forum:
https://boards.cruisecritic.com/forum/386-florida-departures/
Here is the forum where you want to ask/research this issue. Lots of great info to peruse. Link:
https://boards.cruisecritic.com/forum/499-cruisetravel-insurance/
If you already splurged on an aft-facing balcony how much more do you want to splurge on a Haven cabin? Is that a budget killer?
Personally for me, I wouldn't. That's money towards the next cruise. π