Vivarium for crested

Any critiques? It's an 18x18x18 (want ot exchange it for the 18x18x24, but can't find it anywhere) exo terra terrarium. I have 3 plants, a 6' vine, a feeding dish & "bed-a-beast" for substrate. The weather took a turn for the colder, so I will have to cover up 1/2 the screen top to maintain humidity.
If I can find the larger terrarium locally, I will switch to that & add layered substrate so that I can plant the plants directly into it at a later date...
Thanks for looking & your comments!