I had a similar issue last year. I had 1000 SPY callspreads expiring which were close to the upper strike and I didn't have nearly enough money to buy 100,000 SPY (about 12MM notional).
My broker said that if both legs got exercised I didn't have any problem. If one leg (my long leg) was in the money, I would have a margin call on monday, but my options would not be abandoned. So I would be taking a weekend punt on a huge notional.
My broker said that if both legs got exercised I didn't have any problem. If one leg (my long leg) was in the money, I would have a margin call on monday, but my options would not be abandoned. So I would be taking a weekend punt on a huge notional.

