No Insulation in Enclosed Bottom

Take a look at what you paid compared to other RV's that might be considered "All Season" RV's. I don't know anything about your RV but my guess is that it was never designed to be used in anything other than what most people consider to be the RVing season (late Spring to late Fall). Little or no insulation would be required to use that RV during those time periods. If you plan to use your RV during any extreme cold weather you might need to do some after market modifications or find an RV designed to handle those kinds of extremes. My 1988 Prevost has kept me toasty warm during -25 degree winters in Detroit but few RV's are built to handle those extremes as few RVers have any interest in going there when those kinds of temperatures exist.

Various levels of 'insulation' just as there are 'entry level' to 'high end' rigs.

While I have no comment on Tracer Air or on Prime Time Manufacturing, when I looked up your rig compared to mine, yours is one foot longer and has another slide. The difference between our rigs, or to compare a heavy duty travel trailer like an Arctic Fox, is in overall weight. Similar size units can weigh less, or up to a ton more.

This weight is made up in the construction process, and wall thickness, floor insulation, under belly treatment, literally every part of the heavier units is a bit tougher or thicker.