Testing Ping latency but not increasing my licensing cost

I’ve got 2 sites that are overseas.  For simplicity let’s call them sites A and B.  They both connect back to HQ via VPN tunnels over an SDWan connection.  Site A has a local logicmonitor collector and Site B does not.
Occasionally the SDWan will have issues.  LogicMonitor will alert me that there is an above average ping RTT between the collector at HQ and site B (the site with no local collector).  Since site A has a local collector, the ping is always about 1ms.  What I’d like is to have a ping sensor that’s going to run over the VPN to both sites.  This way if I’m getting a high RTT alert and it’s both sites, I’d start my investigation with the SDWan provider.  If I’m getting high RTT alert but it’s only 1 site, then I’d start my investigation with the local ISPs.  
I can think of a few options but I don’t like either of them. 1. I can ditch the local collector at Site A and have him huff all the SNMP data over the tunnel to the collector at HQ, just like Site B does.  I really don’t want to push that data over the wire when I can have a local collector right there.  2. Internal Web Ping, this works great but is apparently not part of my licensing structure.  I already pay LogicMon like $$,$$$/year and I’ve no interest in increasing my costs. 
Suggestions on how I can accomplish what I’d like to do?