Definitely dress for the cold and possible rain. In my experience, snow is better than rain (as while it's colder, snow mostly doesn't stick to you and you can stay dry).
I would personally go ahead and park hop, depending on overall park hours on the day you go. While I agree DS is a mess right now, it also means there are even less things to do there so you can knock out the few things and then focus on
Disneyland Paris. I think the Tower of Terror is a must (as it's the best version in my view) and the shows there are great....I would not miss Mickey and the Magician (which also offers Premier Access), Together is good as well and they have a new Dr Strange/Wanda/Agatha night show that looks pretty good as well (there's a good
YouTube summary that was just posted here:
).
There will also likely be some refurbs in January due to the lower crowd levels, so you may not even fill a full day at Disneyland alone.
Tickets are now demand/date based pricing. Check to see if Klook is offering any discounts. If you're US based, check your credit card offers as well. My Amex just had a Klook offer for cash back. There are otherwise few discounts on offer coming from the US. There are sometimes offers locally.
As for Premiere Access, I would buy a la carte what you need given it's January. I doubt most rides will require it. I think best value is for Crush's Coaster. I have also purchased in the past for Mickey and the Magician, the Lion King Rythyms of the Pride Lands and for the fireworks. Probably not necessary for any of these three in January....I would personally only opt for Crush's Coaster.
