One of the titles for the 7 of Wands is "Valor" (or "Valour"), which indicates exceptional courage in the face of daunting odds - the stuff heroes are made of. Six against one is a valid expression of this idea. I've always noted, when the card is upright, that the single combatant is holding the high ground (a distinct advantage in historical military terms), and it might even be said that he has the "moral high ground" in that he has the right of the situation. It's a "valiant underdog" card with the opportunity to win the day due to superior positioning, and the antithesis of the "might makes right" philosophy.
Reversed, it could mean being overwhelmed by adversity, a victory of sheer numbers over strategy. There is a cliche that goes "Discretion is the better part of valor," said when you believe it is wise to be careful and avoid unnecessary risks. It suggests that an orderly retreat rather than outright defeat or surrender could be the best option in this case. If I were to relate this thought to the High Priestess, it might mean "folding your tents and sneaking quietly into the night," keeping your own counsel with the conviction that you're still morally justified. To me, reversed 7 of Wands looks like a "no win" situation from the first blow; call it a "non-starter" - or at least a fierce uphill struggle - in terms of any kind of enterprise.