Pay attention to this man, he speaks the truth.

I drove to Kilauea from Waikoloa twice, once each way. I'm an amateur volcanology student, and it was interesting to finally put eyes on the famous Mauna Loa 1919, 1926 and 1950 flows--but the snail-on-NyQuil pace through Kailua-Kona was beyond the pale.

This might seem stupid, but if I had to do it again (and I will, LOL) I'd take 19 through ITO, then 11 past HVP and on to South Point and even further north. And then turn around and retrace. Sure, you're going around your elbow, but I'd rather be driving at speed and seeing the same things twice than being stuck in Hippie Central for two hours like I was in Kona. The tank of gas you buy in Hilo will last you, and any roadfood you want you can get in Volcano town until you get to real food in Hilo or Kamuela.