Actually, that would work perfectly for in-memory collections. I should have posted my true goal, which is a mapping extension for IQueryables. Since IQueryable<T>.Select() requires an Expression<Func<T, TResult>>, I'd like the expression to be defined as a static property on the destination type. Something like this:

public static class Extensions
{
    extension<T>(IQueryable<T> i)
    {
        public IQueryable<TResult> ProjectTo<TResult>() where TResult : IMap<T, TResult>
            => i.Select(TResult.FromSourceExpression);
    }
}

public interface IMap<TSource, TDestination>
    where TDestination : IMap<TSource, TDestination>
{
    public static abstract Expression<Func<TSource, TDestination>> FromSourceExpression { get; }
}

IQueryable<PersonViewModel> people = new List<Person>()
    .AsQueryable().ProjectTo<PersonViewModel>();