I find it amazing how many women on here think its completely fine to be ignored and forgotten by their "dates" for days, even weeks on end. And are quite happy to do it themselves, too. I mean, its fine if its FWB - you see someone occasionally but hardly communicate in between your meetings - but I assume people like OP are dating with the prospect of being in a serious relationship, so why such low standard? You need to be shown a consistent level of interest, it shouldn't pewter out or go up and down, and if it was a lot of texts for weeks and then no response I would be asking questions, too.
If anything, it shows that it takes very little for this guy to completely forget about OP as soon as some "fun" appears on the scene, he did not even respond to her texts asking him how he was - which, if anything, is quite rude.
I totally get it - he may have been busy, there could have been bad signal where he was, a lot of reasons - but he could have told you what is going on or at least could have asked you how your Christmas was when he was back. Messaging something like "sorry, really busy with the family, shit signal here, will chat when I'm back" would not have kill him. Also, when he got back, did he ask her how her Christmas was? Did he even say - "sorry, I was so busy, I ignored you, are you ok?" I imagine myself in this situation - someone I know, a friend (not even a date) is alone at Christmas - I would definitely not ignore them and would check with them to see how they are. And this is not a friend, this is someone you say you care about!!
OP, this guy is showing you where you are on his list of priorities. I doubt its games or anything malicious but if someone was really "into you" they would not do that - and he comes across as emotionally immature and selfish. I would also find his desire for constant texts when its suited him very annoying. I actually think you should have not accepted that. Your communication should have not been 100% by text, you are not teenagers.
Throw him back in and find another, a bit more emotionally mature one.