You could have a look at @kyrofa 's Nextcloud snap which bundles Apache and something for Let’s Encrypt. I think the difficulty would be in getting Apache to look for its configuration in a non read-only location.
Yeah, Nextcloud uses both Apache and Let’s Encrypt. Feel free to check it out here. There is also a blog series discussing each component of the initial snap. It’s grown a bit since then, but it does discuss how Apache was snapped.