Maybe, but probably not. Is it capable of getting in? Sure. Getting out? I don't know, but I doubt it. It is too slow and I doubt they could get out to gas without alerting the enemy to their bearing. Any tankers nearby would come under attack, which we could defend fine, but again give egress bearing hints to everything in the area. I would want something up there that could defend itself.
A "nearby" tanker for a B-2 over the DPRK would be somewhere around Guam.