Given a travel related situation, and given a specific question about the situation, summarize the question into a title

I am planning to book an early morning flight from Reykjavik to Berlin via Wow air, its departure time is 6:10 am.

How easy it is to reach Keflavik airport early, is it easy to get airport commute so early in morning?

I can see all Wow air Europe flights depart almost at similar times, so airport will be crowded, any idea at what should one plan to reach airport?

Edit:

Correct above, its Keflavik airport not Reykjavik but its the main airport for International flights.

Update:

I booked Grayline pickup for 3am and it dropped me at airport by 3:50am. I had no problems and reached the boarding area well in time and even submitted my tax refund form.
Catching early morning flight in Reykjavik