The College of Cardinals is the electorate here. There are 135 voting-eligible members (Cardinals under the age of 80), although Varican law allows a maximum of 120 voting members. Not sure how they'll square that.

At present, 80% of the 135 were appointed by Francis. A two-thirds majority is necessary for election, so if nearly all of the Francis Cardinals stick together for a progressive candidate, it should be okay, unless they stick to the 120 maximum and lop off 15 Francis Cardinals. Only 5 JPII Cardinals left, which is good. My uneducated guess is Parolin (familiarity among the College) or de Rocha (continuity).