Hey Thom,
I'm a little late to this game, but here are some other thoughts:
Can you check with your DSL provider to see what you current data usage is like? That can help to determine if a satellite package is going to provide you with enough data. Compared to my cell phone, it can be less expensive to get a higher end data package on a smart phone and use that as a tether than it is to get satellite. Surprisingly, when I'm on the right 4g cell, it can be faster than my home internet service. And often times, the 3g is more reliable given power outages and storms at that cut power to my home. Also, depending on the satellite carrier, once you hit the cap, that's it until the next month without some begging, pleading, or paying a decent surcharge.
I'll second the idea of renting a small office in your local town. I don't know what your home life is like, but if you have things that can always use attention, renting some private space could be worthwhile. Around here you'll pay between $6.95-8.95/ft^2 per year on a lease. If you pick up a 150/ft^2 office, that's $1050-1350 a year for a place to setup shop. Add internet, electricity, and a few other fees and you're at $120-150/mo for a dedicated space, possibly less if you can work out of what is essentially a closet, which you can find too. Depending on your wife's needs you could share it.