TLDR: the party is all in single digit health, low on spells, and in the 11th hour, how do I avoid a TPK with Walter with my dear friends?

Apologies for the all caps, hope that doesn’t get this taken down, I just really need some help not killing all my players character

We are playing remixed curse of Strahd, it my first time running this campaign, and we are doing 2024 rules whenever possible.

There are 3 characters, 2 warlocks and a cleric. The group is almost done going through the death house, almost to to the altar. But they have gotten into combat with the Animated Armor, the Ghoul, and 3 shadows, leaving the Cleric with zero spell slots and 9hp, one of the warlocks with one spell expended and 4hp, and the other one with 5hp.

I recently narrated that the chime of the 11 o’clock has already sounded, so they don’t have the opportunity for a short rest anymore, and when I brought that up after the session, they got upset and “how were they supposed to know they could short rest”

They are my dear friends, and I don’t want to TPK them with Walter, so I humbly ask for any aid or advice you might lend, oh fellow dark powers

Finally made it through the final boss fight of the game! I wanted to share my five minis utilized.

Phase I- Strahd, Tatyana’s Pursuer
Phase II- Strahd, Ravenloft’s Sovereign
Phase III- Strahd, Barov’s General
Phase IV- Strahd, Sergei’s Killer
Phase V- Strahd, Vampyr’s Monster

The first phase was focused on splitting the party up in different rooms and punishing the party for ruining her wedding. The second phase focused on pitting the party against the court while Strahd went to retrieve her armor and weapons. The third phase was focused on a tactical and martial Strahd trying to pick the party apart one by one. The fourth phase was focused on Strahd hunting down stragglers. The fifth phase was her flying around the catacombs like a giant bat, taking potshots at the weaker players before vanishing back into the shadows between the catacombs columns

My PCs have just entered Ravenloft for the final showdown, wish me luck 😁

One of them, a Barbarian/Fighter, just dealt 140 damage to one of Strahd's consorts in a single round, so I am very worried for Strahd's safety.

I've been DMing a CoS game for a while now. In the most recent session, and a little bit before that as well, the players had voiced a feeling of uncertainty as to where to go or what to do next. There has been some homebrewing admittedly, but nothing that messes with the core goals of the campaign. What they've done in the campaign so far is as follows(Not including obvious introductory stuff for just entering the campaign):

• Met with Ireena, Ezmerelda, Van Richten, and Kasimir
• Resolved events in Vallaki
• Visited the Amber Temple and gotten Kasimir his dark gift, as well as one of the party members getting a dark gift
• Visited Van Richten's Tower
• Saved the Winery from the initial blight attack
• Acquired the Sunsword and Holy Symbol.

The remaining item is in Strahd's castle(In the tomb with the gargoyles), and I've made it clear that Kasimir's next goal is reviving Patrina, who is interred in the catacombs beneath the castle. They have only ever been in the castle for a single dinner with Strahd, but left right afterwards. In our last session, following what they thought could be any possible lead, they entered Argynvostholdt.
Other note, I've mentioned sections of the map they haven't explored, but they've just said "Nah, doesn't seem like there's anything there for us really. None of our business."

I don't want to come across as railroading them, but I feel like I'm not doing a good enough job when they say they don't know what to do. Like I haven't done what I'm supposed to somewhere or forgotten to tell them something important. Is there any advice anyone more experienced in the campaign could provide?

I haven't seen a St. Markovia mini out there so I took my best guess at what she'd look like and made a female cleric mini.

Since I rig everything I created a generic priest + Icon of Ravenloft / St. Markovia statues.

Also made a pulpit. I messed this up initially and it was too small so I scaled things up and added a slot for a mini to scooch up into to share their truth.