It's not uncommon for the last remaining seats to be E+. Whether or not you'll be the ones to be assigned them is anybody's guess.

Unless you are particularly tall, and the extra leg room will make a big difference in your comfort, I'd wait. You can check back frequently, on the website or app, and see if seats you'd like open up. Otherwise, I'd wait to see what I'm assigned. That flight isn't all that long so being separated for three-hours wouldn't be worth spending $140 to me.