We're both in Russia and will be here until her immigrant visa is ready, and we occasionally live in a nearby country for however long to keep my visa compliant in Russia. This was indicated in our application but the USCIS account info shows me living at my US mailing address. A lawyer we consulted advised us not to change this and stated that it shouldn't cause any complications or delays. The lawyers and folks we've consulted with are about 50/50 on whether the I-129F trick actually works (the trick being, it leads to I-130 processing instead of your I-129F - when they get to it). Based on current timelines we're seeing on here, Lawfully and elsewhere, it seems the I-130 will probably beat the I-129F anyway. Still, can't hurt, as it is free to file! Good free insurance to some extent, I suppose.
You can use Ask Emma to request a live agent on the USCIS website. They will be able to inform you of the current service center. You can also call USCIS as well to request this information. I'm not familiar with NE (other than the USCIS website estimates) but from what I've seen with CA, I'd expect to start seeing approvals in the next month or so for May I-130 filers. Each case is its own deal though. As we've seen on one end, some have already been approved! Let's keep in touch!