jatti

Simple reason is there is no need for the closest service center to handle the I-130. Unless an interview is required (very rare for a standalone I-130) - in which case it is transferred to a local USCIS field office - where the petition is processed relative to the petitioner's address has no bearing on the process.

Looks like Chicago in OP's case: https://www.uscis.gov/i-130-addresses

Note, if you send the petition package from abroad, use DHL or FedEx, etc. and the courier delivery address in Chicago.  The foreign spouse will interview either in the country where they live, (Canada/Montreal) or country of citizenship, (India/Mumbai).

Unfortunately seems like petitions aren't really assigned based off where you live/where your mailing address is, no one really knows for sure how they assign petitions to service centers (I've seen people in Maryland get sent all the way to Nebraska instead of just to Potomac), so what address you put won't affect where it goes, it's up in the air pretty much, you won't know for sure where it will be until you get the receipt number

At the nearest that has an immigrant Visa unit,  in Canada its only Montreal and in India its only Mumbai 

You can file from anywhere in the world. You just have to send it to the Lockbox (either Chicago or Phoenix I believe). 
 
It will be 8-12 months for the I-130 to be approved and another 3-5 months to interview. He can interview at the nearest Embassy/Consulate to where he lives. 

Or longer if you need and drag your feet at nvc

You can, you will have to send it from India to the lockbox in the US. Keep in mind though, you will want to find a family member or close friend whom you can put down for US mailing address for your notices and receipts to go to. The process is around 12-14 months right now on average

File from India, just will need more stamps.

You can file a petition from abroad