There is nothing more studied or labored-upon by pollsters than the turnout / likely-voter adjustments they make to the raw data. With a bit of noise, the adjustments get more accurate over time. You should assume that the polls are accurately measuring motivation, to the extent it impacts turnout, absent good reason to believe otherwise.
Also, as a general matter, the Republican turnout advantage in the South, especially in “low-motivation” situations, has been badly eroded by the Democrats GOTV operation: terrific technology and personnel, aided by a brace of voting options (absentee as of right, early voting, Sunday voting, etc.)
The polls have been notoriously inaccurate during the last several elections. No informed person assumes they are accurate now. We’ll find out on Nov. 5.