I travel from Denver to Copper or Steamboat several times a week all winter. I got my 4WD FEH Jan 2nd and have had no issues so far. I can go up to floyd hill from Denver at 65-70mph without issue unless someone hits the breaks in front of me. Keeping your momentum up by anticipating traffic patterns helps a lot. Otherwise you'll get back up to speed, just don't expect it to be the under 6seconds I used to get in my wrx.

BTW I've been averaging 27mpg with 1 trip to Copper and a week of commuting to the Tech Center from Denver. When just in town without mtn trips I'm getting 30-31mpg.