JST3AA 3-wire Cable lenght

how long this wire can be?

Can i replace this with a longer cable? like a Cat5 (network) cable?

I want to place the Eblock thermometer 1 to 2 feet away from the panda

Yes it will work but he longer the cable the more off reading you will have.

I will experiment a little

I would like to know this too.
Could you post your findings when you are done testing?
Thank you!