Waiting on ADR cancellation for large party

[4boysandme]

Hello! I am hoping to make an ADR for Ohana dinner on Nov. 23rd for 8 people. Do you think I would be better off when I search trying to get a 4 person reservation? And then hopefully another 4 person one will pop up over the next couple of weeks. Can I then combine them somehow? We all have to sit together...it's my mom's 60th birthday. Or do I just need to search for 8 constantly? Thank you!!