I had my dryer without a vent for quite sometime.. only con was there was more lint to vaccum and super super hot.. not complaining in winter about that.. lol

so I think you could go without for a while.. what concerned me was the kitties getting inside and stuck..

silly boys.. there must be a way to have it blocked from them.. not sure how feasible it is but maybe a hard pvc vent.. or a board on the side and top so the back is enclosed..

will think about it for a while