Heating in a Granny flat

[Fordy40]

I currently stay in a granny flat which is basically a single room with all the amenities. The temperature is starting to drop now in South Africa and I would like to keep my t's warmer than the room gets (10 degrees celcius). It is not viable to heat the entire room and my handyman skills are not good enough to build a heat cabinet! I had thought of making a heat bath or a simple aquarium heater in a vase with water. Another option that I have read on the threads is a oil-filled heater on a timer.
T's (Enclosure)
G. Pulchripes MM 20cm (Exo terra Small low)
B. Albopilosum 12cm (Exo terra faunararium)
P. Ornata 7cm (500ml Deli cup)
P. Metallica 6cm (500ml Deli cup)
GBB 3cm (150ml deli cup)

Any ideas are welcome. Heat mats here tend to be horribly inadequate (hot and cold patches)

 

[viper69]

@cold blood is a master at this. He can keep a T warm at the South Pole if he had to

 

[nicodimus22]

I'm sure you could do this with a larger tub and heater if need be.