If the drummer was wobbly, you should set the tempo accordingly
and snap to that. I recommend doing this a measure or two at a
time instead of a long sequence .. the results can be pretty "off"
if you do minutes at a time.
If drummer was really wobbly .. you'll have to pick something to
align to .. kick or snare .. pick whatever was the most "on" and extract
the tempo from that.
As has been noted, elastic audio can be a replacement for BD .. i prefer
it now myself .. just be sure and select and/or group the regions you want
to work on together .. otherwise, you're going to get some phase
the PT accelerated videos on elastic audio (on the digi.com website) are
quite good as a starter. Click PT 7.4 Videos