Moving clownfish to smaller tank

[Clownydowntown]

So I’m going on vacation to another country next month. The problem is that I have a clownfish (1-1.5 inches) in my 20 gallon. The plan is that I’m gonna move him/her to a 2 gallon and give it to a friend to take care of them while I’m away. Is this okay? I’m going on vacation for a whole month

 

[CoralB]

What about filter , water changes , feeding , heater, etc. I personally wouldn’t put him in less than a 5-10 gallon