A friend did DCF a year ago in Montreal. Have the USC email the Montreal consulate today with a subject line like "Direct Consular Filing -- Recent job offer in US". Explain the situation briefly, no need to attach any documents yet. They should respond within a few business days asking for him to submit scans of the first documents (I-130 (start filling out this weekend), job offer letter, US Passport, etc). Once it's accepted to do DCF, the USC can move (or wait, but not move before acceptance), but the Canadian must wait until approval. In my friend's case they got an appointment within a few weeks, with the USC and maybe the immigrant (I forget) needing to attend in Montreal (no way around this). They should then approve the I-130 after the meeting in Montreal, and then the process is like all I-130 cases, they will put the Canadian in line for a visa interview (again in Montreal, just the Canadian attends), usually in a few months. If you follow the steps carefully on VJ, and get your documents (e.g. birth certificate, any police certificates from other countries (but wait for the Canadian ones until asked), etc.) prepared beforehand (check the Canada forum), you could be moving in 3-6 months (they took 6 months, because of a third country police certificate, but it could have been 4).
This is the fastest, simplest way to move legally, you will get a green card on entry meaning you'll be eligible to work and travel abroad and get health insurance immediately, and you will get to the US faster than 99% of foreigners. Yes it'd still suck to be separated from your partner, but you've really lucked out in getting the fastest track. Take it, study up on the process on VJ, and you'll be there in no time. (And then three years later apply to become a USC so you can become a dual citizen and have the freedom to move back to Canada or elsewhere on short notice and never have to deal with US immigration again.) Bon voyage!
