Happily married, we were in a polyamoris relationship with woman, now miss another female,should we try again?

My husband and I (myself being bisexual but in a monogamous marriage), through a turn of many life changing events...became emotionally, sexually, and spiritually involved with our best friend. We were all very close and happy. We had agreed on a monigamous polyamoris relationship; Husband, wife, and girlfriend. However due to some unfortunate circumstances she went a seperate way although her love for us never faded. A month and a half ago, after only 8 months since she went out on her own, she is truly gone. We had kept close in heart and had fully intended on us all being together again very soon. Now, she is never coming home. She passed away of an overdose in a strange involvement with some bad people or one anyway. Very sad long story...from love to death. We have grieved along with everyone else who was lucky enough to know her. She is always missed. So not only have I lost my very best friend...I also lost that female that shared our intimate moments. We're missing that. Should we try again with someone new? And how would we even find her? So much involved...not sure