Anyone doing the Great Loop 2020 might want to read the following https://www.mvr.usace.army.mil/Missions/Navigation/Navigation-Status/
Yes, already loopers altering plans. In fact, we were considering doing it again next year. Now looks like if one plans it, they better plan on not coming down until November and when it does open, there will be a long line of commercial ships waiting. Discussions of Westrec keeping one Chicago marina open past the end of October for loopers.
I wouldn't do it because then you're having to deal with Freezing temperatures and a long back log of commercial traffix.