Lazydays RV Resort at the corner of I-75 and I-4. https://www.lazydays.com/locations/f...rida/rv-resort
Bay Bayou RV Resort is between Tampa and St. Pete where all the spring training games are played. https://www.baybayou.com/
Both of these are Top-of-the-line RV resorts in the $50 to $70 per night range. You may be able to reserve a place at one of these. The cheaper State Parks will be booked up a year in advance with snowbirds.
Traveler's Rest is in Dade City. Its not really that far away. Tampa St. Pete metro is 50+ miles from end-to-end. Dade City is just outside the metro area. Many people commute daily from Dade City to Tampa to work. There aren't many campgrounds inside the metro area.
2018 Globetrotter 27Q, 32 nights 4,935 miles, 600W Solar, PD4655L, 6V Batteries, ProPride, 16" Michelin's, 2019 F250 PSD
Sold: 2017 Flying Cloud 25FB, 316 nights 40,150 miles, 400W Solar
Sold: 2013 Casita SD17 89 nights 16,200 miles
Solar Production: 213 kWh in 248 days of use