I want to be clear that when I say "Early Gothics," I mean more like The Castle of Otranto (1764) than Underworld (2003). Maybe we could even expand that circle to include the early novels that have strong Gothic tendencies; I'm thinking of stuff like Samuel Richardson's Pamela (1740) and Clarissa (1748)--so let's start by giving this zombie novel a woman's name (probably).
The reason why I think Pamela has a Gothic edge is because there's a shared sense of dread and uncertainty to a lot of these novels; and in many of them--like Ann Radcliffe's Mysteries of Udolpho (1794)--there's a sense of isolation and imprisonment for the heroine. These are women who are usually protecting their virtue from dangerous men, while being unable to leave the manor-house/castle for a variety of reasons.
So let's add one more reason they can't leave: zombies!
Sure, zombies are usually more related to a non-Gothic horror tradition--the tradition of splatter rather than shudder horror. Zombies tend to be messy eaters and also to often have a messy end. (See, for instance, the hero with lawnmower scene of Dead Alive. Or better yet--don't.) But maybe we can re-enliven (wah-wah!) the zombie story by taking it a little away from its roots.
In Gothics, we often have worries about possible ghosts and secrets of the past that come to haunt the living. (In Otranto, it's the fact that the ruler is a murderous usurper, which comes back to haunt his family.) Why not take those skeletons-in-the-closet and add some rotting flesh to it. In fact, let's lean into the whole "zombie as horde" issue: instead of just being haunted by the past, maybe the people are haunted by their class structure--all the poor people that are needed to keep this sort of rich house running.
A house you can't leave (or, as in many zombie stories, a prison, an apartment complex, a boarded-up high school); a terrible threat from inside the house; and the return of the past and of exploitation.
Why aren't you writing... Zombie Early Gothics?