What you will find is that you get damp from below - not from the soil, but moist air from your body condensing in the bedding (and carpet) below you. This is difficult to deal with (unless you sleep in a hammock). Look at getting something like pallets under your carpet layer, so that air can circulate.
This was my biggest problem when living under canvas for any length of time, even in winter with the stove going full on the damp from below wasa pain, either try the sub floor (and post the results, I for one would be very interested) or be prepared for a lot of drying out as part of the morning routine.
I still think you need to look at preventing the soil inside and immediately outside from becoming sodden and trodden into mud - the UK climate is very good at producing mud. You are obviously good at weaving green wood - what about weaving something to go in the doorway so that people don't tread the soil into mud?
I found stepping stones worked well.