what are you suggestions regards trading periods
The comparison, for let's say 2015,2016,2017 (or I don't know where you start your reference) is out of the context since different trend, different types of hype, different scenarios (especially exchange issues, global news) etc. happens at those time.
Generally, there's no favorable season or not. That's how volatile crypto is. Proper analyzation is the one you need to plan for an entry point whatever the time is.
Anyways, if you were able to get a good grind from that season then I understand why you conclude that.