"Roomy inside" and "large trunk" are vague enough to let you trick yourself into buying something bigger than you really need.
Figure out your worst-case scenario of most people/stuff you'll have to fit (be specific). Then ask yourself how often that will actually be necessary. If 5% of the time you need to haul a bunch more stuff/people, get what fits your needs 95% of the time and rent a bigger car once in a while when you need it.
Do you have a car too? If so, what do you drive? If you're concerned about space, a two-car couple can optimize so one of the cars is bigger, but the other can remain small and efficient. My girlfriend and I have this setup. We have a large station wagon and a tiny subcompact. I commute in the subcompact, and the wagon only gets driven when we absolutely need the cargo room (which is often enough to justify owning it in the first place).
Leather, sunroof, etc. Fine fine, most cars are available with those options if you absolutely want them.
As far as "4wd or whatever is good in snow...." A normal front-wheel-drive car with decent snow tires will outperform a 4WD car with all-season tires in the winter. If you're concerned about snow performance, get a second set of wheels with snow tires on them, and switch them out for the winter months (you can do it yourself or have a tire shop do the switch). The extra cost of snow tires is pretty low, as your primary tires then last longer due to less use. 4WD is a performance feature, not a safety feature. If you're driving on paved roads with less than a foot of unplowed snow, you don't need it.
Quantify "good on gas." 25MPG is good for a pickup truck, 90MPG is good for a motorcycle. Try for 35+MPG. The gains past that don't net you as much as it seems as they are nonlinear (going from 20 to 30MPG saves you more money on gas than going from 35 to 60MPG).
Unless you have a reason not to, the standard recommendation of Japanese compacts/hatchbacks probably applies. Civic/Fit/Corolla/Matrix/Vibe/etc.