I travelled a great deal during my Showbusiness career. I had a small folding table, with an altar cloth. Yes, I had candle sticks, and a censor, but they are not absolutely necessary. Just a table, with a nice cloth; red or green, is all that is really required. It is what is in your Mind that is important, not what is on the altar.
Yes, a scarf would be fine. The altar, and all the "tools" that go with it, are merely there to help concentration.I just happened to have a small table,but it is not necessary. Even sitting in a quiet spot, under a tree perhaps, one can still meditate,visualise,ground and centre.