I have a couple of questions that I hope somebody would be able to answer. I have an award ticket booked last year for travel in May at the 60,000 level for Europe, and I would like to make a date change on the outbound, to leave one day later. The return would stay the same. I've been calling for the last week or so, but no availabilities at the same level. Yesterday, I was searching using one way for my outbound, and I found an itinerary one way for the date I wanted for 60,000 miles, so I placed it on hold. Here are my questions:

1. If I call SkyMiles Reservations, would they be able to transfer the availabilities on the one-way ON HOLD itinerary to my existing itinerary to replace the outbound segments? Or are mileage requirements for one-way different from return, and the two wouldn't match?

2. The itinerary I have on hold has a layover of over 9 hours in CVG. Are there any implications of such a long layover if I don't plan on leaving the airport? Such as having to check in again, or needing to get another boarding pass?

Thanks.