I understand what you mean. I don't have dc but a few years ago I remember getting to 27th December and feeling irritated that it felt Christmas had passed me by as I'd kept myself so busy I didn't actually give myself time to enjoy it.
We changed few things here and they helped - feel free to ignore though!
Use a physical calendar put in anything booked/arranged and write in 'evening at home' or 'film night' etc so the time is literally blocked out.
Look at buying 'experience' presents rather than things that need collecting/wrapping although I am a weirdo who loves wrapping and finds it relaxing
This year for example, I've bought tickets to a favourite musical for my mum, auntie, cousin and sister.
Past presents have included cinema vouchers, restaurant vouchers, gig tickets etc. May not work with your dc if they're very young but could help with others?
Aim to have the majority of the shopping complete in November.
Now this one is a tradition for me and is not everyone's cup of tea but I have a 'wrapping evening' when DH is out. I put the Christmas lights on, get something nice to drink, something to eat (can be as nice as a turkey sandwich or as basic as a chocolate orange) and set up the table with my sellotape dispenser, various rolls of wrapping paper, gift tags and pens.
Stick a Christmas film on and work my way through the presents until they're all wrapped.
I used to get through a fair few films but it's lessened over the last few years - my only rules are that the first film must be Muppets Christmas Carol, annoyingly shaped presents are tackled first and all presents must be done by the end of night 
Lapland sounds very exciting - it's on my bucket list of places to go
How old are your dc? Assuming they'll get the full Christmas and Santa magic experience?