Insect repellent spray and coils. Fold as fold may. No problem. Cold winter, mosquitoes retreat. I've tarped many many nights. Insects? Easy to defeat their purpose.Different strokes, but I don't consider sprays and coils as an adequate solution. I tend to be a bug magnet though and also would prefer to keep the amount of DEET or other repellents on my skin at a minimum.
On the other hand we met one guy who was doing fine and was about 70% of the way toward completing the TA with no tent, no tarp, and no bivy. He was traveling really light and said he slept in the open, under picnic pavilions, and even in doorways of public buildings.