I'm not sure, if more people vote early, then I expect turnout overall would tend to be higher, and that would favor Democrats more in the midterms.
Who knows for sure, this article seems to be getting downvoted, it is a shitty headline; I was more interested in the overall turnout.
Speaking of which, this article says turnout is higher:
According to data released Oct. 22 by the State Board of Elections and Ethics Enforcement, voters cast 430,841 ballots over opening weekend, far outstripping 2014’s opening weekend of 297,599 ballots for that midterm cycle. The 2018 early voting period is 18 days; 2014’s consisted of 10 days.