but not able to go just yet for wake turbulence separation. (Intersection departures behind 737s are very common where I fly.
You shouldn't be given the clearance until it's safe, or at least will be safe when you get airborne. For example if I need two minutes for wake turbulence (or separation for that matter) I would normally give you the clearance at about 1:40 after the previous airborne time, knowing that by the time you have read it back, powered up, rolled and rotated you'll have the required spacing/separation.