Disbelieving Ahlul Kitab will be in Hell-Fire:

ومن يبتغ غير الإسلام دينا فلن يقبل منه وهو في الآخرة من الخاسرين

 

And whoever desires other than Islam as religion - never will it be accepted from him, and he, in the Hereafter, will be among the losers.

 

^{— Quran 3:85}

إن الذين يكفرون بالله ورسله ويريدون أن يفرقوا بين الله ورسله ويقولون نؤمن ببعض ونكفر ببعض ويريدون أن يتخذوا بين ذلك سبيلا

 

أولئك هم الكافرون حقًّا وأعتدنا للكافرين عذابًا مهينًا

 

Indeed, those who disbelieve in Allah and His messengers and wish to discriminate between Allah and His messengers and say, "We believe in some and disbelieve in others," and wish to adopt a way in between -

 

Those are the disbelievers, truly. And We have prepared for the disbelievers a humiliating punishment.

 

^{— Quran 4:150-151}

لا يسمع بي أحد من هذه الأمة يهودي ولا نصراني ثم لم يؤمن بالذي أرسلت به إلا كان من أصحاب النار

 

Whoever amongst the community of Jews or Christians hears about me, but does not affirm his belief in that with which I have been sent and dies in this state, he shall be but one of the denizens of Hell-Fire.

 

^{— Sahih Muslim}

If your hypothetical wife died without accepting Islam then there is no reason for her fate to be any different just because she was married to a Muslim, indeed the verse of the Quran that permits such a marriage, itself concludes as follows:

ومن يكفر بالإيمان فقد حبط عمله وهو في الآخرة من الخاسرين

 

And whoever denies the faith - his work has become worthless, and he, in the Hereafter, will be among the losers.

 

^{— Quran 5:5}

And even marriage to great Prophets does not avail a disbeliever any concession, so how could the status of the wife of a common Muslim be any better?

ضرب الله مثلا للذين كفروا امرأت نوح وامرأت لوط كانتا تحت عبدين من عبادنا صالحين فخانتاهما فلم يغنيا عنهما من الله شيئا وقيل ادخلا النار مع الداخلين

 

Allah presents an example of those who disbelieved: the wife of Noah and the wife of Lot. They were under two of Our righteous servants but betrayed them, so those prophets did not avail them from Allah at all, and it was said, "Enter the Fire with those who enter."

 

^{— Quran 66:10}

would i act as an intercessor? 

There is no intercession or forgiveness for disbelievers:

إن تستغفر لهم سبعين مرة فلن يغفر الله لهم ذلك بأنهم كفروا بالله ورسوله

 

If you should ask forgiveness for them seventy times - never will Allah forgive them. That is because they disbelieved in Allah and His Messenger.

 

^{— Quran 9:80}

إن الله لعن الكافرين وأعد لهم سعيراً خالدين فيها أبداً لا يجدون ولياً ولا نصيراً

 

Indeed, Allah has cursed the disbelievers and prepared for them a Blaze. Abiding therein forever, they will not find a protector or a helper.

 

^{—Quran 33:64-65}

Disbelieving Ahlul Kitab will be in Hell-Fire:

ومن يبتغ غير الإسلام دينا فلن يقبل منه وهو في الآخرة من الخاسرين

And whoever desires other than Islam as religion - never will it be accepted from him, and he, in the Hereafter, will be among the losers.

^{— Quran 3:85}

إن الذين يكفرون بالله ورسله ويريدون أن يفرقوا بين الله ورسله ويقولون نؤمن ببعض ونكفر ببعض ويريدون أن يتخذوا بين ذلك سبيلا

أولئك هم الكافرون حقًّا وأعتدنا للكافرين عذابًا مهينًا

Indeed, those who disbelieve in Allah and His messengers and wish to discriminate between Allah and His messengers and say, "We believe in some and disbelieve in others," and wish to adopt a way in between -

Those are the disbelievers, truly. And We have prepared for the disbelievers a humiliating punishment.

^{— Quran 4:150-151}

لا يسمع بي أحد من هذه الأمة يهودي ولا نصراني ثم لم يؤمن بالذي أرسلت به إلا كان من أصحاب النار

Whoever amongst the community of Jews or Christians hears about me, but does not affirm his belief in that with which I have been sent and dies in this state, he shall be but one of the denizens of Hell-Fire.

^{— Sahih Muslim}

If your hypothetical wife died without accepting Islam then there is no reason for her fate to be any different just because she was married to a Muslim, indeed the verse of the Quran that permits such a marriage, itself concludes as follows:

ومن يكفر بالإيمان فقد حبط عمله وهو في الآخرة من الخاسرين

And whoever denies the faith - his work has become worthless, and he, in the Hereafter, will be among the losers.

^{— Quran 5:5}

And even marriage to great Prophets does not avail a disbeliever any concession, so how could the status of the wife of a common Muslim be any better?

ضرب الله مثلا للذين كفروا امرأت نوح وامرأت لوط كانتا تحت عبدين من عبادنا صالحين فخانتاهما فلم يغنيا عنهما من الله شيئا وقيل ادخلا النار مع الداخلين

Allah presents an example of those who disbelieved: the wife of Noah and the wife of Lot. They were under two of Our righteous servants but betrayed them, so those prophets did not avail them from Allah at all, and it was said, "Enter the Fire with those who enter."

^{— Quran 66:10}

would i act as an intercessor? 

There is no intercession or forgiveness for disbelievers:

إن تستغفر لهم سبعين مرة فلن يغفر الله لهم ذلك بأنهم كفروا بالله ورسوله

If you should ask forgiveness for them seventy times - never will Allah forgive them. That is because they disbelieved in Allah and His Messenger.

^{— Quran 9:80}

إن الله لعن الكافرين وأعد لهم سعيراً خالدين فيها أبداً لا يجدون ولياً ولا نصيراً

Indeed, Allah has cursed the disbelievers and prepared for them a Blaze. Abiding therein forever, they will not find a protector or a helper.

^{—Quran 33:64-65}