Well the rain tarp is a double edged sword. If you have it tight against the roof of the tent it will increase your condensation issue, if you have good ventilation, door at both ends window on the side kind of thing that can be taken care of.
If you suspend the tarp above the tent a couple things happen. Worst is the wind damn thing will bounce and flap all night.
If it snows the tarp will sag, and depending how you have the eve suspended to keep the tarp of the tent, the snow and ice will build up there. The heat from the tent will melt the snow at the top of the tarp but not at the edges. With the tarp on the tent the snow will just slide off with just a little shake of the tie town ropes. You still get some freezing on the edges but that’s easy to deal with. After 50 or 60 years off trying to figure out what’s best I just put the tarp on top but rig the three corners away from the wood stove so I can fold them back if we’re not getting real wet weather, snow or rain. Really helps with the moisture. I treat the roof of the tents every couple of years, I’m not worried about rain starting while we are out hunting, just button things up when we get back. That plus windows and or a door at the back depending on which of three wall tents I’m using takes care of the condensation.
With my 16x20 I put two bales of straw on the ground under the tent. No floor, This is very helpful if the ground is frozen. Keeps if from thawing during your stay, adding more moisture, provides great insulation against the cold, if it rains and you end up with water running under the tent, the straw keeps the floor tarps near the cots and such from getting wet.
Hunting in NE Oregon I always put the tarp on the tent. Even if the forcast is for dry weather the next ten days. In Montana, if it’s going to be cold and maybe a little snow I dont worry about the tarp as I trust my canvas. I don’t care what anybody says Montana snow is a hell of a lot dryer than Oregon snow.
