We leave ours open. To put ours away it's more than sliding it in though. Clear bench tops, Disconnect stove fold and put it away, fold extensions, push crates back into trailer (it swings into the space where the food tubs live).
Always have the annexe roof up, and after a wet night a while ago we always put up the end wall to keep the rain out which also keeps the dew out. Now if it rains it doesn't get wet.
As for the drafts, the previous owners taped a thin foam mat over the bed base to keep the drafts out. Seems to work well, but means the inner access hatch can't be used.