Pretty much all of NH and VT will be very scenic at that time.

It's difficult to pinpoint particular places to visit, but I can offer a few suggestions.
In Vermont, the two major roads that run along the Green Mountains are Route 7 / 7A (on the west side) and Route 100 (on the east side). Personally, I love 7A between Bennington and Manchester (check out the Mt. Equinox Skyline Drive), but 100 from Killington northward is much more scenic than Route 7. Route 100 should provide plenty of great photographic opportunities.
Another option is a more haphazard route through the eastern side of the state, with its numerous postcard-perfect New England villages (choose this route if you're looking for 18th century villages and rolling hills rather than mountain scenery). Some of the oft-photographed villages (from south to north) are: Grafton, Springfield, Ludlow, Woodstock, Pomfret, Tunbridge, East Corinth, East Topsham, Peacham, Danville, etc. Between Ludlow and Woodstock you could also swing over into Cornish, NH to see all the covered bridges and the St-Gaudens estate.
As for New Hampshire, once again there are tons of possible routes through the state, but as far as scenery goes you'll definitely want to see the White Mountains. These are more rugged and arguably more impressive than the Green Mountains in VT; there are great photo opportunities in Franconia Notch State Park, Weeks State Park, Crawford Notch State Park, Echo Lake - Cathedral Ledge State Park, along the Kancamagus Highway and the Mt. Washington Auto Road (if the weather is clear).
You might also consider the Lakes Region just south of the mountains -- two of my favorite viewpoints are from the Castle in the Clouds in Moultonborough (overlooking Lake Winnepesaukee) and from Rattlesnake Mtn. in Holderness (overlooking Squam Lake).
As far as wildlife is concerned, it's not an exact science. Bear sightings are probably the most difficult. Your chances to see moose increase exponentially the further north you go; anywhere north of the mountains in NH or in the Northeast Kingdom of VT is prime moose territory. Route 3 in far Northern NH is often called "Moose Alley," although you'll probably have to explore the backroads as well. The locals might give you tips, but don't get your hopes too high -- there's always the possibility you might not see any at all.
You will need at least 3 days to do VT, NH, and then up to Montreal. I suppose it could be done in 2 but you'd be really pushing it.