Can a lower (mini) face lift be done with incisions behind the ear instead of in front?

Any type of face lift will require small incisions in front of the ear to remove redundant skin and allow for good visualization of structures that need to be corrected. This incision is placed in preauricular crease and it is less visible then the crease-fold most patients have in this site. I do not think that incision (scar) of this kind should be of much concern.
You should consult a board certified plastic surgeon with good reputation in facial rejuvenation and discuss your options, see patient pre and postoperative photos and/or talk to patient(s) who  recently have similar surgery. Good luck.

A mini lift tends to give mini results, and we rarely ever perform them. A full set of photographs of the face and an in-person examination are usually required to make the determination about what type of facelift to perform. In our practice, we  usually perform a high-SMAS lower face and neck lift which accomplishes tightening loose facial and neck skin, lifting the jowls, tightening loose facial neck muscles, removal of fatty deposits in the neck which also includes a platysma plasty. The incisions are in front and behind the ears, and it's very important to make them minimally detectable by your surgeon.  Look for a surgeon who produces natural results consistently. For more information and many before-and-after examples of face lifting, please see the link and the video below