Context / Question

I've worked on numerous .NET projects that have been required to persist data and have usually ended up using a Repository pattern. Does anyone know of a good strategy for removing as much boilerplate code without sacrificing code base scalability?

Inheritance Strategy

Because so much of the Repository code is boiler plate and needs to be repeated I normally create a base class to cover the basics like exception handling, logging and transaction support as well as a few basic CRUD methods:

public abstract class BaseRepository<T> where T : IEntity
{
    protected void ExecuteQuery(Action query)
    {
        //Do Transaction Support / Error Handling / Logging
        query();
    }       

    //CRUD Methods:
    public virtual T GetByID(int id){}
    public virtual IEnumerable<T> GetAll(int id){}
    public virtual void Add (T Entity){}
    public virtual void Update(T Entity){}
    public virtual void Delete(T Entity){}
}

So this works well when I have a simple domain, I can quickly create a DRY repository class for each entity. However, this starts to break down when the domain gets more complex. Lets say a new entity is introduced that does not allow updates. I can break up base classes and move the Update method into a different class:

public abstract class BaseRepositorySimple<T> where T : IEntity
{
    protected void ExecuteQuery(Action query);

    public virtual T GetByID(int id){}
    public virtual IEnumerable<T> GetAll(int id){}
    public virtual void Add (T entity){}
    public void Delete(T entity){}
}

public abstract class BaseRepositoryWithUpdate<T> :
    BaseRepositorySimple<T> where T : IEntity
{
     public virtual void Update(T entity){}
}

This solution does not scale well. Let's say I have sever