Yes flamingo campground Is open year round providing no COVID closures or act of nature.

Can't say for sure, but think they are open year round. You can look up Everglades national Park campground.

Jan and Feb are the best months of the year. Least mosquitos (depending on the weather that does not mean none). Cooler weather is better to keep the skeeters down. Awesome place. Great birding, DO the ranger activities.