Let the yuri get cooked! What a lovable imouto, I hope they get to move two ways-wise but I suppose that'd end the manga, so let's see how much quality time those two can share. I find it quite accurate for that era, even in Scandinavian countries people would sleep naked but using pelts to keep themselves warmer, but this indeed varies from country to country. The total opposite of all this would be Spain, where not only Catholics avoided bathing but also hid the naked body (even alone) the more zealots they were, same for breakfast (fasting was strickly followed from March to April for instance, but certain religious orders would fast all year around). I can't even fathom how bad it smelled in Middle Ages to the point people would get "visions", but it's more than comprehensible that illneses would ravage entire settlements.