From someone that just force started our RIR flock with one chick, DO IT!
I just got a RIR pullet and a Lorp pullet. My first on both. Dad wanted to raise RIRs anyways and I was already getting the lorp for a pet and a way to help my niece get over her fear of chickens (she 4). Mom says we're chicken poor now, just wait till we start getting 2 RIRs a week. I love Nutrena Chick Days!