Dude that whole inferred shit isn't as true as they want you to believe! As long as you don't have exhaust vents pumping straight out of the house their FLIR can't see through your walls! Cut a hole in the subfloor and pump it under the house but make sure you filter is on point cause it will funk your whole house up and all around the outside if not.
Check out lighthouse hydro tents! Excellent product for the money. Lots of us have them!! I'm not affiliated with them at all. Just good stuff for the money!