Those portable garages make poor hunt camp tents. Why like the previous post stated "they don't breath", that means "condensation" and lots of it. In post #27 of this thread I described how we put two tarps over our canvas wall tent. There are 2 good reasons for doing that: a)It kept the rain and the snow out. b)The canvas would breath and allow the water vapor out but when it hit the cold plastic it would form condensation but it was on the "outside" of the tent when it formed, so we had zero condensation issues in the tent even with 4 of us. We cooked in a fabricated vestibule out the front on the other side of the closed canvas end flaps.
I have seen folks in recent years set up with those portable garages for camps and cooking inside them. Even with a wood stove going there were hundreds of water droplets dripping from the roof. Cooking outside or in a separate tent would greatly help reduce water vapor but just living and breathing in a enclosed plastic tent with no ventilation will produce enough water vapor to make your life inside miserable. Every nice day they had lines strung up all over the trees drying out there sleeping bags. The days it rained they were miserable inside as it was dam near as wet inside the tent as out due to warm most air inside the tent and when it came in contact with the cold plastic tent surface it forms condensation.
If you have ever seen winter use army tents they are double walled the main reason is to help greatly reduce condensation issues.