I have to move and will mix in a really small room for the next couple of weeks/month. My desk barely fits in there. It's like 1,50 x 3m or something. I will have to use it, there is no other way. Do you think this could make my mixes much worse?
Headphones
carpet all over the walls is a bad move. It's not that getting a really dead room as necessarily a bad thing, it's a matter of personal preference.
BUT
just carpet gives you a dead room at high frequencies while leaving longer reverb times in the mids and lows. This is unbalanced and highly undesirable.