We were working on framing the open area of our soon to be Pea pair pen. It is 11X 18.5... and will be fenced and netted. We are attaching their 'keep out of the rain, snow, nesting area"... ( we have mild winters mid south. We are thinking 6-8 ft. long, and 6 ft. wide? with a roof sloping from the top (8 ft) towards the back to drain.... (trying to estimate materials and trying to save costs as much as possible). Is 6X6 or 6x8 enough shelter for rainy days...?Mostly we get rain...