I have always found Trek's frames are a good fit for me. I think the collective reasoning is what were called "gravel bikes" last year are now being branded "adventure bikes". More "off-pavement" than "off-road".
To that end, as my experience last week revealed to me, the fat bike is good on all surfaces.
Trek rep at the Chequamegon Fat Tire Festival said the 920 would be available in February.
Ride safe,
Hans