I often ask myself: if the preposition can be placed before the verb and not after it, will the construction "as for to" be grammatically correct in comparison to "as for" or "as to"?
As for to where you are going, "The place is horrible" they say.
In comparison to:
What do you think friends?
Edit: To those whom it concerns "as for/to" means "changing the subject".
to refers to movement towards.
I am going to London.
So, when referring to the place itself, and not to the act of traveling to the place, the preposition is likely to be dropped:
As for the place you're going, I hear it's rather dangerous.
Compare:
Did I just hear you say you're from Austin? That's where I'm going on vacation.
But a speaker could just as well have in mind the intention to visit and be referring to that intention and the trip as much as to the place itself:
As for the place you're going to, I hear it's rather dangerous.
going to can express intention periphrastically:
As for the place you're going to go (to), I hear it's rather dangerous.
"As for where you're going to" is the way to say this, though as the commenters suggest, it would be common(er?) to drop the "to".
As you suspect, "As to where you're going" is not begging for that same "to" at the end.
If you replace "where" with a noun phrase you'll get a much greater demand for that "to":
As for the house you're going to...
Either way, "as for to" is so strange that it led me and perhaps one commenter to misparse your sentence and rule it un-English. A closer look reveals it to be theoretically acceptable ("As for the question of to which house you're going"), but very improbable.
