After standing around getting nearly hypothermic for two hours in -20F two years ago I decided that this year (-5F), I'd only wait outside for an hour. Hurrah! They opened the door an hour earlier this year so, with my heaviest winter layers, I waited inside!
"Opening Day" is a tradition no one really needs to go through to get good reservations anymore but it is an experience everyone who enjoys the park should endure at least once. I see it almost like a reunion ... park staff are especially helpful and enthusiastic and I almost always come away with some information not found elsewhere.
The number of campers and the number of visitors to Millinocket was the lowest I'd seen in the 20 years I'd been going in alternate years. I use it as an excuse to hike etc. for a couple days prior and it makes for some interesting destinations at a very quiet time.
On Monday, under clear crisp skies and single digit temps, we decided to head up to the North Gate, never having been there before and curious about the ride in, distance to the gate from the end of the plowed road (1 1/2 miles), and accommodations near that end of the park. The ride was so beautiful with views stretching from Katahdin to the Travelers that we changed our hiking plans and decided to walk the Tote Road (a snowmobile trail in winter). One our right was the frozen Grand Lake Matagamon, on our left the rough face of Horse Mountain ... only 800' but a dramatic gateway and turkey vulture roost.
The scenery, fresh air and anticipation of our trip next summer was perfect therapy for ... the Patriots ... go Steelers, Packers ... anybody but the Jets!
I'd recommend Baxter Park's Opening Day tradition very highly, especially when it includes some opportunity to get outside in the area.
Meanwhile, heed Peakbaggers advice, you don't need reservations for busy trailhead parking if you are staying in the Park but you do need to get there before the parking lot fills up.