Ohio State is still a long shot to get the #1 seed, but with a ND loss to Clemson and an Alabama loss to either Auburn or Florida in the SECCG, am undefeated B1G champion OSU is a lock for #1. 
 

Playing at a bowl with fans would certainly be nice. California has been much less lax about allowing fans in the stands for NFL games this year. I would doubt the Rose Bowl would be much different. I’m not entirely sure who makes that decision, but I’m assuming the California state government gets the final say. 
 

that being said, the Sugar Bowl could allow fans. The New Orleans Governor starting allowing Saints fan in the Superdome about a month ago. However, OSU does love the Rose Bowl and even a fanless one would be hard to pass up. 
 

I’m of the belief that if we play Alabama, Florida, or somehow Clemson (I don’t see how we could get 1 and them get 4 but it’s possible I suppose) then we head to the Rose Bowl because any of those teams have an advantage in less travel time. But a game against Notre Dame, BYU, or UC and we go to the Sugar Bowl.