Price adjustment for negative working capital and seasonal business

Hi guys,

I am about to put an offer on a business with negative working capital (customer invoice paid in a few days but payables at 30 days; no inventory). The business also is seasonal and by the time we close the very busy season will be behind us, so effectively leaving us from day 1 with few receivables and quite significant payables.
How would you approach the negotiation with the seller?

I was thinking introducing in the LOI an "uncommitted cash balance", effectively making sure the cash balance left on the balance sheet would be free of invoice, payables raised and accrued expenses before the closing date.
Then having the price adjustment clause pegged on the uncommitted cash balance.
What do you think of it? Curious to see how searchers approached the issue

Thanks a lot for your help!
Tom