Nordstream 1 was 1222km, and Britpipe now, is 60km shorter.
Boston to Lisbon is 5100km. Churchill Falls (home of a giant hydro dam project in Labrador Canada which got screwed by Hydro-Quebec because the only via transit was through Quebec), would be just under 4000km subsea.
The transit contract expires in 2039 I believe...
It really doesn't make much sense to connect Europe and North America.
[1] https://en.wikipedia.org/wiki/Ultra-high-voltage_electricity...