The chance of Black Grouse Lekking in very early April (07th)

I asked this in the photography section but may find an answer here. I am planning to visit a Scottish Black Grouse Lekking site on April the 07th however I am concerned I will be too early to see any birds display as this is so early in the season. Can anyone advise if this is the case? A 3 hour drive and 4 hours in a hide for no photos will be disappointing to say the least!