Caves and the camping areas that accompany them seem to have a distressing habit of being located in frost hollows, or otherwise just being in cold places. Why couldn’t we have a nice big chunk of limestone down on the coast in Murramarang National Park (because geology, that’s why)? So to deal with this unfortunate fact, you’ll want a decent sleeping bag. I won’t go into the intricacies of sleeping-baggery, but there’s two basic varieties, camping bags (cheap(er), heavy, and bulky) and bushwalking bags (small, light(er), and expensive). These both come in down and synthetic options. Both have pros and cons, but don’t believe any of the hype telling you that you MUST buy a synthetic bag if it could get damp.
For caving use in this part of the world, it doesn’t much much what you get, as we mostly car camp. There are some walk in areas (Church Creek and Colong notably among them), but NUCC rarely visits these areas. So if you like bushwalking, or plan to go to more remote caving areas, shell out for an expensive down bushwalking bag. Otherwise, a cheap N nasty synthetic bag will be fine. Importantly, make sure that it has been properly tested to the EN13537 scheme, and if it hasn’t treat any claims about warmth sceptically. Make sure you know which point on the EN13537 scheme your bag’s rating refers to, and how cold you sleep. As a very, very general guide, a woman should buy a bag based on the ‘comfort’ rating, and a man based on the ’lower limit’ rating. To be warm in most situations in the caving areas NUCC visits in winter, you’ll need a bag with an appropriate rating of around -5*C. Be warned though, this might leave you sweaty and uncomfortable in summer!
Honestly, whatever is cheap and easily available and works for you. The blue closed cell foam mats are fine, although not as warm or as comfortable as inflated mats. This is not a critical piece of gear, although you will likely have a miserable night without one. I have a regular length Sea to Summit Comfort Light Insulated and personally very much like it. It’s light enough that I can take it bushwalking, and well insulated enough to keep me warm in most situations. Coupled with a pillow, my feet don’t stick off the end (I’m 195cm tall). It also didn’t cost a proverbial arm and a leg (just and arm).
Highly recommended for sitting round a campfire in. They’re cheap at most outdoors stores. Don’t get one that is too bulky, or the person giving you a lift is likely to chuck a tanty. You also don’t want one that is too small and lightweight, as those ones are frequently made of poor quality materials and die very, very quickly. If you’re feeling particularly stingy, the Green Sheds at Mugga and Mitchell have plenty of pre-loved options.
Camping is one of those things where it is possible to build up such a range of camping junk (intended to make camping easier and more fun) that camping actually becomes harder and less enjoyable. Go for a walk around any self-respecting camping store (or the garage of any camper who has been camping for more than a couple of years), and you’ll find plenty of stuff that fits into this category. Don’t avoid the stuff, if purchased and used judiciously, it can indeed make camping more fun! But the best advice is to go over your camping gear after any trip, and ask yourself if you used it on the trip? If not, do you really need it, and is there something else you already have an use that could do the same thing? If the answers are no, no, and yes, then leave it behind on the next trip, and try out the something else!