If you write to DL, you'll probably get more.

I had a mechanical that left me stuck in HKG this summer. I was on a coach ticket upgraded to biz using a REAL SWU (ala NW).

When checking on the flight the day before, it showed delayed 8 hours. I was able to get the hotel to let me check out late, so no need to camp out at the airport or lounge.

I called DL, and had them change my connecting flight, and they said they'd provide an overnight hotel in DTW. Next morning check my email, and they've canceled the flight. They have me rescheduled for 2 days later.

Not acceptable to me. I want the direct flight, which is not available. I check CO and find they have seats in Biz, and amazingly DL will put me in one of the last two seats. It helps to call in as soon as you realize there is going to be a problem.

So, I have to stay in HKG a day more. When I return, I get DL to pay for the extra night hotel and food. They give me original routing credit, but not promo miles they were running. It takes a lot of work to finally get that last bit of mileage credit. They also throw some miles at me. Less than a domestic award, but acceptable.

You certainly have to stick to your guns, and be reasonable. DL is not going to pay $800 a night for a hotel. Or $400 for dinner.