I’d advocate for the later flight “just because stuff happens”. In that case they’d be carted to the Admirals Club or Flagship Lounge because of class of service eligibility if they’re in Business until it’s time to board the flight.

As well, “Priority boarding and re-accommodation status” in case they’re scheduled on the earlier flight and miss it.

The original plan with hotel overnight might still be the best, given change and FSS fees, etc.

My suggestion to you is to call the FSS right in DFW with your list of questions. They know their own service better than anyone else and can offer informed opinions about your options. They would know about costs, timing, airport hotels, etc. I really think, under the circumstances, the FSS is your best bet for your parents.

I have stayed in the Grand Hyatt Hotel right in the DFW airport and was very pleased. The escalator to the hotel is right off the airport concourse in Terminal D. The next morning, I went from my room to my Terminal D departure gate in about 15 minutes. The room was really nice and thoroughly sound-proofed.

As someone who does have to use wheelchair service occasionally, my recommendation is the later flight or stick with the original plan of staying over (and staying at the Grand Hyatt DFW for ease of connections in the morning). If they get through immigration and customs quickly (and I've had it happen), they could try to stand by for the earlier flight, without the stress of "what if I don't make that flight."

That being said, do not underestimate how tiring a long flight can be, especially when one is dealing with a health issue. There's been more than once though when I've gotten to DFW and wished I had a hotel for the night because I felt like my body just couldn't take anymore. The option to get a hotel and continue on the next day may be the best option for them.

Again, thank you all for your assistance.