Yeah, I'm with the other posters, unless there's specific drama or something you're trying to get away from, it's easy enough to offload any dragons you're not feeling anymore. You probably have a decent coli dragon or two in there it would probably be easier to have in terms of getting back into the swing of things, not to mention items - if you didn't have the habit of hoardselling, you're probably sitting on a few stacks of things that new Swipp/den tasks/etc ask for that you could make a nice profit off of now.
In terms of relearning - what do you actually want to do? New g1 projects? NotN is coming up, of course, cue the flood of cheap baby Nocs that might take your fancy. Just make a bunch of profit and see where it goes? Again, NotN is a good time for it, maybe level some of that fodder before then if you want, to get back in the habit of coli-ing (it'll probably come back to you fast, but feel free to post here again (or on site) if there are specific things you don't remember), then come the holiday, farm whatever venue you like for Strange Chests and the Swipp components thereof.
Re: jump back in or restart?
In terms of relearning - what do you actually want to do? New g1 projects? NotN is coming up, of course, cue the flood of cheap baby Nocs that might take your fancy. Just make a bunch of profit and see where it goes? Again, NotN is a good time for it, maybe level some of that fodder before then if you want, to get back in the habit of coli-ing (it'll probably come back to you fast, but feel free to post here again (or on site) if there are specific things you don't remember), then come the holiday, farm whatever venue you like for Strange Chests and the Swipp components thereof.