Mind the Gap

We still have a one night gap in our itinerary for February. I've been trying to book a night at the Indian Hill Ranch RV Site but they are completely unresponsive. I've now sent them two emails (one back in November) and left a message on their answer phone, to no avail. I can't decide whether we should give up and book somewhere else, or whether we should wing it and just turn up. The RV campsite bible says that this is more scenic than the close-at-hand alternative, but finding ourselves with nowhere would be a tremendous pain in the wazoo.