Something to look at? ... not much out there
http://www.bing.com/mapspreview?q=Intersta+5+and+hiway+46+rv&mkt=en&FORM=HDRSC4But there's an RV park in Lost Hills, think it used to be a KOA, block from 5/46
http://losthillsrvpark.com/NOT a destination but we stayed there one night stopover. Cant say all that quite so close to freeway, stations etc but convenient fuel food services. Havent been over 46 in a while but curious whats at Blackwells corner now? Didnt use to be any thing but a place to buy nuts.
The 58 is a really nice drive if you have time, once you get into the hills. Very scenic. It'll add a good hour or better but once over if you turn left/south toward Santa Margartia Lake (though almost empty) but nice campground, trails, theres also KOA just before the lake. Or right/north into town of Santa Margarita and onto 101 to Astacasdero, 41 over to Hiway1/Morro Bay.
All about time...
