Have you considered doing staggered hatches? Use one incubator as an incubator and the other as a hatcher. I'm not going to give you any specific schedule, you can figure that out for yourself, but mid-March is fast approaching.
The advantage of using one as an incubator and the other as a hatcher is that the incubator should not get dirty enough to need to be cleaned. If you space your hatches out well enough you can give it a thorough cleaning between hatches.
You mentioned using pullet eggs. I could give you a long list of things that might go wrong hatching pullet eggs, especially if they are those little bitty ones when they first start to lay, but the reality is you can hatch them. I’ve hatched them. My hatch rates using them are not normally as good as using larger eggs from older chickens. The ones that hatch are much smaller than chicks from normal sized eggs. I’ve had higher mortality with the ones that hatch than normal. Not a lot more, but noticeably more. Every time I’ve hatched pullet eggs I could find something else I could blame that higher mortality on, but it’s only when I hatch pullet eggs I notice the higher mortality rates whether with a broody or in a brooder. I’m talking anywhere from when they first start to lay for maybe 3 weeks after they start laying when I’m talking about pullet eggs. Normally I wait at least a couple of months to set them.
If you do try it, the lower hatch rates might be because of the pullet eggs, not just the weather. It’s sometimes hard to pinpoint the real cause of things.