FYI in the spring summer is way more fun to sleep inside the sand dunes with a parking permit you buy at that lot. The hike up into the dunes is epic but yes this is free and last minute high capacity. Sand dunes camping has a 10 or 15 person per day
The Dyrt has a weird seemingly inaccurate map however the road leading out to the dunes did in fact had a dirt road that branches right off towards the mountain.
The Dyrt map says Mt Blanco road but Apple Maps says lake Como road. They both branch off highway 150. There is obvious signs of dispersed camping used ie firepit and a randomly left behind camping item
The weather I was very skeptical about. thought i would have to book a hotel. Last time I went camping per review off of Idaho springs down Fall River road it was snowed in even tho the main road was fine. After I got through the very snowy and icy mountain pass from Walsenburg to for garland it became very dry and there was no more snow.
This region in Colorado is fair weather all year long. With the exceptions of severe winds sometimes rarely