Just a thought here, as there are no bad outcomes:
If you weren't into racing, which trip would you choose? It sounds to me like it would be Whistler. .....
Consider also that age 57 or 58 is not the end of your physical life. If your are truly paying attention to your body, taking care of yourself and staying in good enough shape to race, I doubt this is the only year you will ever have a shot at winning A Vet. How about a longer-term goal of winning in style by blowing away the rest of the field when you're 60? In that perspective, this year is just practice, building towards your inevitable domination of the racing schedule.
You are absolutely correct there really are no bad outcomes here. To answwer your question, right now going back to Whistler is a higher priority than going back to Aspen/Highlands/Snowmass, not that I would be upset if I had to go there again this season.
I do try to keep myself in shape. But I have 2 virgin knees that have given me signs of trouble recently, but nothing that some good drugs can't take care of....so far. I have a feeling that once one of my knees go my race career will be over. I also know barring any unforseen injuries or ailments, I will ski at a high level well into my 60's and hopefully 70's before I have to start taking the easier way down.
I really appreciate all of the comments and advice. It is getting me stoked for ski season! Oh yeah, race season too.