Go look at he performances on youtube. Some o the best ones are actually done with smaller harps. When I cycled in my younger days, we used to say “It’s not the chassis, it’s “THE MOTOR”. The Mighty Bob Dylan wrote: “She’s got everything she needs, she’s an artist, she don’t look back”
A creed to live by! Be an artist! Make your music from soup cans if you have to!
Seriously, the choice is yours. The big harp may be the way to go, but maybe you should make your music closer to home then. I think you are limiting yourself by feeling limited by a smaller instrument.
But I wish I had a bigger harp!