"New to the Class A world"? Your profile pic shows a tag axle DP. I wish I was so new.

Congratulations!
First, the further south you go the more expensive it gets. Second, the closer you get to the coast the more expensive it gets. Both together and it gets expensive.
Florida is not that wide a state so perhaps you could narrow it down a bit. Meaning more to the center of the state could work out and is likely to be less expensive. Also provide some of your needs and wants. Need to be close the beach or don't care? Need a ton of amenities or is just a pool is OK? Etc.
If you want to avoid cold temps in the winter it's generally believed that you need to stay south of Tampa (and the line it makes to the east coast).
You need to be calling NOW. Most places allow people to reserve for the next year once they've stayed there. That reduces the number of places available for newcomers. Once you find even one place that has an opening, inquire about their cancellation policy. If it's acceptable
reserve it. You can continue to call around looking for a more desirable location and cancel the first one if needed.
You may be in luck this year as some Canadians are making noises about not coming back. The exchange rate and, for some the political climate, are problems for them. While the exchange rate does not look that bad, about $1.35 CAN to $1.00 US the reality is the fees they get charged by their banks makes it really $1.50 CAN to $1 US. That's a lot.
Many places in the south have two month and three month minimum stays so your plan is a good one for the area and time of the year. We often see RV's buttoned up for weeks at a time because the owners decided to take a long cruise or go back for the holidays. That's not unusual at all.
Just make sure the water is turned off, maybe any propane tank is turned off, the air conditioners are on, the slides are pulled in, and any generator Automatic Start is programmed and enabled.
You do not want to come back to a leak because you left the campground spigot turned on. You do not want to come back to mold inside because you tried to save some money and shut the A/C's off. You do not want to come back to a fridge and freezer full of smelly, rotting food because the power went out and the generator did not start to compensate.
Etc.
Expect to spend roughly $2,000 a month plus electricity usage costs. That can add another one or two hundred dollars each month. Or stay at a nice place in Naples and pay around $5,000 a month. Your choice.
Let the campground know when you're leaving and when you getting back. It doesn't hurt to leave a key with them or hide one underneath in case there is a problem. During the winter everyone kind of looks out for everyone else even if not asked. The mandatory length stays tends to keep the riff raff out.
We keep wireless cameras in ours so we can login and see the inside temps as well. Earlier this year a place where we left the motorhome had a lot of tornado warnings. My wife was getting antsy and thought we should go to the campground to check on things. I told her I had just checked the cameras and the motorhome was still upright so we were good. Oddly, that calmed her down.
Good luck,
Ray