I'm running Curse of Strahd for about 5 players. The party is currently level 4 and has managed to travel all the way to Krezk from Barovia after finishing death house, at the behest of Ismark and Ireena.
I estimated travel time based on the map of Barovia provided in the module very roughly. Each hex is supposed to be 1/4 mile, and pg 28 of the module says:
Dangers abound in the land of Barovia. Check for a random encounter after every 30 minutes that the adventurers spend on the roads or in the wilderness. (Don't check if they have already had two random encounters outdoors in the past 12 hours).
I counted roughly 70 hexes along the road from Barovia to Vallaki. This comes out to 17.5 miles, which could be covered in about 5.8 hours on foot assuming a Normal travel pace of 3 mph. At a fast pace (e.g. you were in a hurry to get the hell out of town because you stole a girl from a vampire) you'd get there in around 4.4 hours.
I went with that for the players, and they had a pretty quiet walk to Vallaki. They ran into
a skeletal rider and some mountain men so-called "berserkers" who are described as keeping their distance in the module,
neither of which slowed them down since both encounters were non-combat. Per the book, I didn't check for any additional encounters.
Anyways, by the time they got around to leaving Vallaki for Krezk the next day, I wasn't sure if they should have been making such swift progress. I could have had Strahd or some other force arbitrarily waylay them, but I was still getting used to my big boy GM boots and didn't want to do that. They ended up making it to Krezk that following day, where some fun stuff happened with the Abbott.
I was a little unprepared for them to make such swift progress in a single session and skip over all the hooks in Barovia and Vallaki. I did my best to keep the game going anyways, but I wasn't sure if I was missing something either implied or outright stated in the module that should make it more difficult to walk across Strahd's domain. I understand that Strahd himself might have made things more difficult (especially concerning Ireena), but should the overland travel itself be more arduous/take more time, given a party who sticks to traveling during the day?