You could just try switching the MF inserts for a combination of hemp topped with bamboo.
We use fitted nappies covered by wool at night, as it's very breathable option; nappies seem less damp come morning. We use Holden's Landing Bedbugs, Flutterby Fluff Nights and Bumhuggers. We have used Baby Beehinds and Swaddlebees OVOS successfully, too. If you prefer pockets, I know other people like Nappies by Minki pockets for overnight. But, again, you'd be better ditching the MF stuffing.