You max loss is $5 (the width of the spread) excluding the credit you originally received for this trade.
So if you received $1 credit then your max loss is $4. (per share, so $400 in absolute terms)
i would probably buy in the last 5 minutes of the trade of day of expiry if its in the moneyRare, but Max loss could be more what you expect. 290 get's exercised and overnight the SPY loses - pick a number. Exercise you buy at 290 less premium you received. Not common, but it moved 100 points today. Trade out early
Why?Trade out of it irrelevant of price.