Flongies - will they stink in the morning?

Cool!

Some flongies have a soaker sewn inside to make them more reliable. But I imagine any thick fleece trousers would do

You could always sew in an extra layer...

I'm not sure microfleece would be very effective, but I can test it out, I might try her in a fitted and mircofleece sleepsuit for a bit later and see how we get on