Update:
Applied the fix today. I did opt for socket saver solution. Everything worked ok- socket saver cleared out the hub from what I could tell, but- new pipe was only going in about .5", to which- I was uncomfortable with that. Would have liked a little more pipe into the hub. I bored out the hole quite a few times, and...no new material was coming out. Not sure if there was perhaps a small sliver on the side I couldn't fully see that was causing blockage on the new pipe or not.
In any event, I opted for the Fernco coupling solution at that point. Think it worked well. The coupling was "1.5 hub"/"1.5 pipe". This may have been the best solution anyway, as it provides flexibility at the stress point now. Also added a pipe strap at the elbow.
Thanks to all for your help. I now have knowledge, tools and supplies to make abs repairs in the future if I need to do anything at the campsite- woot!