New ball python adoption.

[Bogertophis]

...whats the most a pad can cover? ....

Actually, I'd normally agree that 1/3 to 1/2 the cage floor is safest, but when I had a large BCI, I used the wide (11") Flexwatt under 2/3 of her tank (yes glass tank):
First off the 11" heat strip was about half as wide as the tank, so I ran it down the center, from one end of the tank, leaving the other 1/3 of the floor unheated...but
OVER that heated 2/3, I also custom-made a hide (waterproofed wood & tile board top, 5" tall) that fit over the same area, so actually, the top of that hide served as
additional floor space..."her second story". I did use warming lights over that hide, & she loved basking there, but she also used equally the inside of the hide (with
maximum warmth) & the unheated end of the enclosure. Goes without saying all heat was regulated, & her tank was insulated so that the UTH didn't HAVE to run so
hot in the first place (& contrary to what is commonly repeated, UTH does raise the ambient warmth as long as the enclosure itself is insulated in some way). She
appeared to be comfortable & healthy, & remained so. So don't be afraid to "think outside the box", that's all I'm saying. Formulas for heat strips are just generalized.

BTW, on top of that giant hide, I kept a clean carpet mat (with non-slip backing) so she had good traction. The hides sold for snakes are mostly slippery plastic, so the
space on top of them is awkward & useless for snakes to crawl on...they slide off.