Poker stars, $10 + $1 NL Hold'em Tournament, 6,000/12,000 Blinds, 1,200 Ante, 7 Players

BigMan1984 (BB): 1,070,405
Sobizzle21 (UTG): 452,309
FouTight (UTG+1): 352,579
mrpemite (MP): 360,390
S.J.Plankton (CO): 641,091
brunomanga (BTN): 365,141
tjeezy17 (SB): 758,807

Pre-Flop: (26,400) As Td dealt to S.J.Plankton (CO)
3 folds, S.J.Plankton raises to 27,666, 2 folds, BigMan1984 raises to 82,800, S.J.Plankton ???

Final 2 tables. Coming into the final 2 I had a big stack ~850k My plan was to play tight until we got close to the FT bubble then open up.

Things haven't gone that well, we are down to 13, and I just played my first hand shoving JJ over mrpemite's KQ shove and losing. To make matters worse the villian in this hand BigMan1984, ran well and became the big stack. He is a good player and he was playing very aggressive, both opening a lot of pots and 3-betting a lot.

So I get ATo in cutoff and its clear to me that this is going to be a decent spot for him to 3-bet me. But there is no way I'm playing so tight I'm not opening ATo in the cutoff. So naturally I get 3-bet. Obviously I feel I'm ahead of his range, but my stack size sucks to 4-bet fold. Should I just call and play ATo in position with 53BB effective? Fold and wait for a better spot? Turn ATo into a bluff and 4-bet?