It depends on the rating, or playing strength of my opponent. Also, it depends on what is a "hopeless position". I imagine at least half of my games reach a position which is "lost", but not "hopeless". If I was playing someone rated 1050, and I had a King vs King+Queen, I may still try for a stalemate.
Resign or continue


It really depends on the skill level of my opponent. If I feel that he is strong enough to convert the advantage to an actual win, then I'll resign. Otherwise, I'll play on.
Are you more likely to resign a hopeless position or stay in for a posible stalemate?