I'm going for a head shot, no matter what the situation.
If it doens't present, simply don't shoot. Just part of the "game" to me.
That said, I've gone to progressively smaller sized shot over the years. I used to "load up" mainly with #5 copper-plated lead. As the diverse offerings of heavier-than-lead shot have become available, I've switched over to them, and opted for smaller-size shot.
The only "situation" where I have a different load is regarding should a follow-up shot be necessary, nothing to do with whether I'm hunting woods or fields.
When turkey season opens, in my chamber will be a load of #7 H-13's. They're throwing a denser pattern than #6 copper-plated lead, and packing a per pellet punch closer to #5 copper-plated lead. Should a follow-up shot be needed, will likely have in reserve some #6 and #5 "heavy" Winchester Extended Range loads. These Winchester pellets are 10% heavier than lead, whereas the H-13's are 20% heavier. But seems the Winchesters produce a little larger (but very uniform) pattern (than the H-13's), that could be of greater value on a wounded and moving bird needing a follow-up.
But truth is, it may matter very little what's in your chamber if you reserve your shooting to head shots at a reasonable high-probability killing distance for your gun/choke. Under 35 yards, may not matter at all, and I'd bet most experienced turkey hunters are taking most birds under 30 yards.
For those who haven't yet tried "heavier" than lead options, would recommend your first trying the Winchester Extended Range shells. These are more readily available and at a better price, and seem to be consistently good performers in most any gun or choke. If you normally shoot #5 copper-plated lead, try these Winchesters in #6 --- comparable per-pellet punch and usually a denser pattern. Unfortunatley, the Winchesters are not available in #7 size. Go with the H-13's. If you can't find straight #7's in the H-13's, the H-13 "Blend" (#5, #6, #7) has still produced denser patterns for me than straight H-13 straight #6's.