The LHR flights to/from DEN usually have R>1. No Polaris lounge though.
Just did a quick search for a couple of days out and seeing R>1 confirmable on LHR to DEN, EWR, IAD, IAD, IAH, LAX, and ORD.
Edit: found SFO with R9 about a week out:
Also seeing DUB-EWR with R7: