Ah! I was one of the lucky ones; I refused to ever have short hair...EVER. I fought for it and fought for it and grew it out when I was young and have had it long most my life. When I began transition I didn't have to deal with the growing out phase, BIG plus to be sure
That said, in my non-existent-experience in this issue, I'd definitely recommend just toughing it out. Wigs aren't cheap, and you don't want to buy some great fancy wig only to outgrow it in a few months! Also, as has been recommended, there are ways to make the sort of shaggy/inbetween look very feminine! One way or another, you don't have much longer to go!