11 day itinerary

How are you traveling between cities? Cesky Krumlov can be awkward or time consuming from Salzburg unless you are driving, but in every one of these towns, you don't need a car while you are there. So, that may affect your desire to be there for one night in December. We spent three nights there in September and loved it, but ended up hiring a private drive from and to Linz to make it happen.

I haven't done things like snowshoeing in Austria, and I believe snow will be very iffy in December, but I think your best bet would be to find one place to stay for 4 nights up in some higher mountains to have a chance at it and to allow you better opportunity to really get out there.

Hallstadt is rEALLY small. I dunno if you want to spend a night and day there. We were there for an afternoon, and felt that we spent too much time. It's really hyped, but pretty low in attractions.

Cesky Krumlov is a cute town with a river but it’s not Salzburg. Possibly consider two nights in Salzburg

I would add one day to Vienna, one less in Prague.
There is a direct train from Vienna to Hallstatt, arriving at lunch time (11:54am). Maybe you could continue your trip the very same day and go to Salzburg.
Going by train from Salzburg to Cesky Krumlov is a bit of a pain, travel time about 5:40 hours, 2 changes, early departure (6:11am).

Thank you for the suggestions!
We've adjusted the trip to
3 nights Vienna
2 nights Hallstatt
2 nights Salzburg
4 nights Prague with day trips out from here (Cesky Krumlov etc)

I think it is worth noting that pretty much everything will be closed Dec, 24 and 25 - as in everything. Dec. 26 is also a public holiday so shops will be closed but attractions may be open. I would stay in Vienna, Salzburg and Prague as there is more likely to be open as opposed to a village over the holidays. Visit Hallstatt as a day trip from Salzburg. Sadly you will miss the Christmas markets. Take the Bean or CK shuttle from Salzburg to Cesky Krumlov if that continues to be your plan.

Fantastic itinerary! Just a friendly reminder: make sure to purchase a vignette for Austria from https://vignettetoll.eu/ to avoid any unexpected fines upon your return home. It's a small but crucial detail that ensures a smooth and trouble-free journey. Safe travels, and enjoy every moment of your trip

https://vignettetoll.eu/ is a reseller. They don't tell you the price until you have entered all data (names, vehicle registration), but I guess you will pay more than the regular price.

Best is to purchase the vignette at a gas station or from a service station of an automobile club.

Buying the vignette online from the original issuer (ASFINAG) makes sense only if you can plan ahead and know what vehicle you will drive, because an 18-day grace period is imposed before the vignette is valid. This is due to legal constraints. European law regulating online purchases permits cancellation within 14 days. To prevent that someboby buys a 10-days vignette online, uses it, and then cancels the purchase in time, the grace period is required. If you get the vignette from a shop, gas station, etc., then it is valid right away.

EDIT:
ASFINAG has made the following changes to the rules governing the Austrian vignette for using the Atutobahn, effective December 1st, 2023:

There is now a new 1-day-vignette for travellers just crossing Austria.
This vignette and the existing 10-days-vignette can now be purchased online having an immediate validity, i.e. without the previous grace period of 18 days.

Good news to know wmt1. Will come in handy.

I agree on a half day in Hallstatt (If you must) and chose another Austrian local for an overnight.