My daughter recently did this trip and had no problem going over George Washington Bridge on a Friday late morning. To avoid George Washington Bridge, exit New Jersey turnpike at route 287 north. Route 287 takes you to New York north of the Tappan Zee Bridge. There may be some traffic here going south to hook up with highways going west to New England, but it shouldn't be impossible. The following directions form 287 to New England are from map quest. I have taken this route not as far as Boston but to Connecticut. The 287 route saves on tolls also. If you do decide to take 95 to go through New York, the worst traffic will be the exit for the bridge on the Jersey side which is backed up all day everyday but it moves; however, take the lower level exit for the bridge. Get yourself an easy pass if you do not already have one. Another piece of advice regarding easy pass is that the left easy pass lanes are generally slower. Even though signs direct drivers to the left lanes early, there are easy pass lanes in the middle and right. If you'd decide to take GWB, you could take take the Henry Hudson Parkway exit which becomes Saw Mill Pkwy and follow the directions below from number 8.
Merge onto I-87 S/I-287 E/New York Trwy S toward I-87 S/Tappan Zee Brg/New York City (Portions toll).
18.7 mi
7.
Take the I-87 S exit toward Saw Mill Pkwy S/New York City.
0.2 mi
8.
Take the NY-119/Saw Mill Pkwy N exit, EXIT 8A, toward Elmsford.
0.8 mi
9.
Merge onto Saw Mill River Pkwy N via the ramp on the left toward Katonah.
18.7 mi
10.
Merge onto I-684 N via the exit on the left.
10.4 mi
11.
Merge onto I-84 E via EXIT 9E toward Danbury (Crossing into Connecticut).
43.3 mi
12.
Merge onto I-691 E via EXIT 27 toward Meriden.
8.7 mi
13.
Merge onto I-91 N via EXIT 11 on the left toward Hartford/Springfield.
16.8 mi
14.
Merge onto CT-15 N/Wilbur Cross Hwy N via EXIT 29 toward I-84 E/E Hartford/Boston.
2.1 mi
15.
CT-15 N/Wilbur Cross Hwy N becomes I-84 E/US-6 E/Wilbur Cross Hwy N.
1.5 mi
16.
Keep left to take I-84 E toward Boston (Portions toll) (Crossing into Massachusetts).
39.2 mi
17.
Merge onto I-90 E/Massachusetts Tpke E toward NH - Maine/Boston (Portions toll).
56.1 mi