Thanks for other people's replies on other threads. I am thinking of taking a late December solo trip to Key West and Miami. Here is my supposed itinerary. I know I might be overplanning but I am trying to figure out how much time I need in each location. Do I need a rental car in either or both locations? Or would it be too much time, money, and difficulty finding parking spots? I have a max of 9 nights based on when my work will be closed between Christmas and New Years. It looks like more is open on Christmas and the day before, in Key West versus Miami/South Beach. But I could be persuaded to do the trip in the reverse order.
Saturday 12/23: Flights to Key West. Find a good grocery store today or 12/24. 1st night
Sunday 12/24: Ernest Hemingway Home (9-5), possibly: Key West Lighthouse (10-5), Southernmost Point marker, Duval Street to Mallory Square. 2nd night
Monday 12/25: Audubon House & Tropical Gardens (9:30-4:15), Mel Fisher Maritime Museum (10-4), Truman Little White House (9:30-4:30) 3rd night
Tuesday 12/26: USCGC Ingham Maritime Museum (10-4), Fort Zachary Taylor Historic State Park (8-5). 4th night
Wednesday 12/27: Bus, plane, or rental car to Miami area, probably South Beach. 5th night.
Thursday 12/28: Jewish museum (10-4), Wilzig museum (10-6, last entry 5pm); possibly Perez museum (11-9 Thursdays). 6th night
Friday 12/29: Vizcaya Museum (9:30-4:30, advance ticket required). If time, a boat tour. 7th night
Saturday 12/30: Fairchild Tropical Botanic Garden (10-5). Possibly a boat tour if not done yet. 8th night
Sunday 12/31: possibly Everglades national park (50 mi drive to Ernest F. Coe visitor center, then Anhinga trail is 4 miles further, 0.8 mi long. Mahogany Hammock Trail is 72 mi from South Beach). 9th night
Monday 1/1: flights back to Michigan
I already went to Florida once so far, in December 2021, for 8 nights. I saw parts of Fort Myers-Sarasota-Tampa-Saint Petersburg-Winter Park. On that trip I arrived in Fort Myers and left from Orlando. I rented a car, which cost about just under $900 for a Kia Soul, for 8 days. I didn't have difficulty finding parking spots. Which might not be relevant because I am planning to go to different locations this time.