I think the true battleground is the culture: the schools, universities, news and entertainment media, Hollywood. The battle will be a decades-long slog, and it is late in the day. Until the tide starts to turn, the role of political battle will be mostly defensive: to prevent further losses and preserve freedom of action for the cultural battle. Trying for offensive gains with inadequate force and on unfavorable terrain is likely to result in serious defeat and loss of positions that could have been defended.
However, with respect to your point:
"Trying for offensive gains with inadequate force and on unfavorable terrain is likely to result in serious defeat and loss of positions that could have been defended"
I disagree on both points. If our forces are inadequate, they will never be stronger until we have a black Swan event. The terrain is not unfavorable but rather the most favorable available among a majority of Republican held conservative states rather than in an electoral college with the numbers are not to our advantage anymore or in the national legislature were, even when we have a nominal majority, establishment Republicans sell us out.
There is the possibility of a moral defeat with the loss of conviction and persistence but that is an imponderable which is difficult to quantify and it might just work in precisely the opposite fashion.