BFG, as for weekday riding I've rode through your hotel area a few times in the morning; but I don't remember bumping into any group rides.

Honestly though, I'm not familiar with riding in that area. However, unless someone with more info chips in, I would suggest avoiding riding on Clairemont Mesa & Kearny Villa during rush hours and night time. Jschen and I have ridden a clockwise loop on Miramar (WB) -> Kearny Villa (SB) -> Clairemont Mesa (EB) ->Genesee (NB). The loop takes about an hour; and I'd suggest finishing this before rush hour starts (@8:30am) as the route passes through numerous freeway on/off-ramps.