IR camouflage clothing is quite inexpensive, such as IRR MoD Genuine issue Smock and Trousers and most IR detection equipment is based on image intensity technology not true Thermal IR using bolometer technology. i.e. movement would be based on the same daylight tactical movement. i.e using cover and stay in the shadows from the cast starlight (unless active IR LED or LASER emitters are used)

Thermal IR using Bolometer is a different story but a wool blanket backed with disruptive pattern mylar cut outs of different thicknesses could be very useful