An article written in February this year said the show currently has 411 hours although their math was questionable with assumed episode length so I bumped it up to 440 hours.

So if you watch 7 hours of one piece per week that would take you just under 63 weeks. Which is about a year and 3 months. Accounting for new episodes let’s call it a year and a half.

Ways to spead it up would be skipping every intro and credits (this was in episode length calculated) and if you watch dub/read fast you can speed up videos anywhere from 1.25 to 2 times speed depending on your comfort level.

It is possible