I have a 4 ft. x 2 ft. x 2 ft. plywood cage that I acquired 15 years ago with my first savannah monitor. I have been reading up on them alot because I want to get a new one and I have noticed a lot of information has changed since I owned my first. This cage I realize is too small for a full grown sav but it will only be temporary. I will be moving in the next year so I will begin work on an appropriate size cage when I have moved. I have some questions about the modifications I intend to make to the current cage to allow for proper living conditions. 1. I plan to sand the inside again so I can reapply more sealant to it because I would like to use bioactive soil and due to the now suggested humidity for them. From what I have seen Minwax polycrylic is most common for above the substrate and I was planning to use FRP to line the substrate area. When I make these siding modifications to the cage, I intend to actually add 2 feet to the height of the cage to allow for a 1 foot layer of substrate for burrowing. Is this information correct and the most cost effective or is there a better way for the price or quality? 2. This cage is also located in my garage so I intend to use 2x2's and 1/2 plywood on the top/bottom/sides to add insulation all around. I live near Amarillo, TX so the winter can and does at times reach below 40 degrees for around 4 months of the year. Do you think that doing this to the cage will add enough insulation to allow for the interior temperature to be maintained? My real concern would be the fact that the front is not insulated due to it being (planning to be) glass. 3. Can anyone confirm that the bioactive soil is a good idea for a Sav or is there a better option? 4. Pay no attention to the current lighting in the cage because that will be my first modification. I am curious thought whether a ceramic heat bulb would be good to have for the nights and winter to help keep the temperature appropriate. Does anyone have experience with these? I have read that if they get wet they can crack so how would the humidity level be for this? Thank you all for reading and any advice you can give.