To Europe from 1870$ with Air Portugal. There is one trick you need to follow, but that's pretty simple.
For this “travel hack” you have to book two oneway tickets instead of one return ticket!
There are two big advantages with oneway tickets, the first one and the most important, the price. And the other one is flexibility, as you may fly back to New York from another city as the one you arrived.
Flights are available the whole year, availability is the best when you look for dates well in advance, but of course not every single date will be available
Here the oneway prices to Europe:
And here the oneway prices back to Boston, you may do as well a free stopover in Lisbon.
The flight back must depart from those two cities as this are the only one offering cheap oneway tickets to Boston.
This shouldn’t be a big concern, as Dublin or Oslo can be reached from alomst everywhere in Europe cheap by airplane. Another possibility is to use your miles/points to get to Dublin or Oslo.
The cheapest option would with inbound from Oslo would be a total for the “return” ticket for 1870$.