I'm writing this, laying in my HH Exp deluxe with a mmss mummy bag on me right now. It is in the lower 50's and raining its butt off. Using the light patrol bag, with a wool blanket under me I am more comfortable than if I was in my bed.
It takes some wriggling about, but I say use what you have to head out in the bush. There is no need to buy pricey UQ and OQ to just simply stay warm in a hammock. I used my issued gear and have been comfortable down in the teens without special pricey hammock gear.
Try out what you have before buying anything.