Just how crowded will Phi Phi be Jan 12-20?

I have been reading here, the listed blog sites (including Tezza's very useful site), The Lonely Planet book, etc Everyone mentions this is the busy season, which I understand, but I am not sure what kind of crowds this means. Is this crowded compared to a an island paradise? Or does this mean you will be fighting for a spot on the sand?

I was in Patnem/Palolem late last January. Is it like that? Is that considered crowded? (I would not call it crowded).

Just trying to get a gauge. Thanks.

You won't be fighting for a spot on the sand. One of the great things about PP is the beaches are loooong. I've been there at peak when Loh Dalum is crowded central and eastern end - hardly anyone down the western end. Ditto on opposite Ton Sai beach - except down the western end here is gorgeous with genuinely deep clean water low tide.
Long Beach is popular but guess what - looooong - enough to be uncrowded in sections. And if you walk 5 minutes over the western headland to Viking's little bay, few people. Walk 10 minutes to the over the eastern headland to Loh Modee and here is a lovely looong beach few people seem to know about. Or take a right off this path past the highest of The Beach Resort's bungalows and 5 minutes gets you to a similar little bay to Vikings, the lightly used beach at Au Poh.
But sure, the place will be crowded. It will be difficult to get a room unbooked. Bars and restaurants will be packed. The little alleys in town will have crowds of people moving thru. Hey, holiday time!

Typical Day on Phi Phi

But seriously, as Tezza says even when the accommodation is full there is still plenty of sand and sea to go around. One place that does get very crowded is Maya Bay during day trips to Phi Phi Leh - literally hundreds of folks clogging the bay looking for Leo Di Caprio's footprints.

Great photo Bob. Our old favourite, Whitehaven, can't compare with that place.