I tend not to do too much online while traveling. What little I do use is most often on my phone (A tracfone, so it's about as far from unlimited as it's possible to get). Mostly it gets used for looking up weather or travel information.
In my experience, RV park wifi has varied from none to practically unusable to barely adequate to really good, but usually more towards the lower end of the scale. Public campgrounds almost always have none. There's also sometimes no reliable cell service at some public campgrounds, for that matter.