Thanks for the warm welcome, Glenn. I definitely want to take my son out with me, though I'll probably do one or two single night outings first to make sure I'm not putting him in an overly uncomfortable or dangerous situation.

You mentioned fleece blankets as inexpensive sleep gear in summer. I've got a couple of those polyester/fleece child-sized blankets, and I've noticed that they are very warm for their weight. I've wondered if I could even make my own cold weather sleeping bag and use this type of inexpensive fleece fabric for fill (less than $5/yd US), but perhaps there're diminishing returns on how warm each successive layer makes it so that adding enough layers would make it heavy?

In any case, I'll get the sleeping bag last as that's likely to be the most expensive, or I'll just suck it up and tote one of my cheap ones if it's warm enough. I think they're 40 degree bags, but I'm a bit cold-natured.