Hi Sweer, yes, 52% is definitely small. I'm very surprised to hear such screens are still being made. How old is the laptop?
74% is on the small-ish side, but I rocked a mid-70s screen for quite a few years, and it really didn't hold me back. It might trouble you for floral photos, or sunrises and sunsets, but from your question, it sounds like you might be indoors? The 74 would be ok; but of course if the 92 is going to come back into stock soon, and you can wait long enough, it would be better.
Your wording of this question concerns me - it sounds as though you consider calibration optional. It is NOT optional. No matter what computer or screen you have, if you intend to work professionally, you must be calibrated.
Therefore, your first step MUST be the purchase of the calibrator. Even the 52 screen you presently have will be a LOT better with calibration.
Your assessment is correct here. External screen is the best option for quality, but completely impractical for dragging along to events.
https://www.damiensymonds.net/2015/07/buying-mac-or-pc.html