Well, from my own experience I can tell that a burnout is sneaky. All is fine, you notice something off here and there, but nothing wild. All managable.
Until one day: “Hi!” sais the burnout. From out of nowwhere.
The major problem with that is that before your first you don’t know the signs - for there are plenty of those. After your first you know 'em and can properly interprete them making avoiding a second quite easy actually - if you are prepared to let go of your previous misconceptions about carreer and money and that.
Now: just being tired is just about the weakest and most untrustable sign, for there are a plethora of reasons to be tired. Running low on vitamis for example - especially vitamin D, the “sun-vitamin” of which a proper game developper naturally does not see much
Generally I too would rather wait a month or three longer - a burnout, being a subclass of the depression, is hard and time-consuming to come out of. Stay healthy (especially mentally)!