1 Night in Pismo Beach

Not in Pismo, but up near Cuesta College is El Chorro regional park. The hookup spaces are very nice but they fill up. But their dry-camping overflow almost always has some spots available. They're good in a pinch.

http://slocountyparks.org/camp/el-chorro/

Get the “Allstays Camp and RV” app. Easy to use, fairly up to date and has phone numbers, photos and if the park has a website that will be there also.

Besides Avila Beach there are at least 7 CGs just south of Pismo Coast Village. Have you tried them?

Not far from Pismo is Avila Beach and Port San Luis Harbor. If traveling on non holidays you can usually find a spot along the side of the road just before Port San Luis. The beach there is dog friendly. 1/4 mile further in Port San Luis there are some back in spots next to Fat Cats diner (Excellent). If those are full there is an overflow RV area on the hill above. The view overlooking the bay is beautiful.

https://www.portsanluis.com/2163/RV-Camping

JT wrote:
Walmart in Arroyo Grande doesn't allow overnight parking, so don't count on that as a fallback if you can't find a spot for an extra day around Pismo.

Most Wal-Marts in California, don't allow overnighting.
Especially along the Coast.

Try Pacific Dunes Ranch, they usually have an opening and they have full hookups. Just a short drive on Dolliver from Pismo Coast Village. About 5 miles.

If it's the 2nd night and if you have reservations/booked on the first night, you'll have priority for no-show campers on the following day. But you have to inform the ranger on duty put that in their bulletin board.

Walmart in Arroyo Grande doesn't allow overnight parking, so don't count on that as a fallback if you can't find a spot for an extra day around Pismo.

For 1 night go to one of the state RV park right next door to Pismo Coast rv park no hook ups but they have a dump station for 1 night. Oceano RV state park 1/4 south 2 blocks from the ocean with hook ups. There is a County RV park 1/2 mile past Pismo Coast.

If it's on short notice, it's near impossible in this time of the year. But good luck anyways.