I agree with DocJ that it's not so much SLAC vs. everyone else, but something to look at on an individual school basis. In general, more prestigious schools will have bigger endowments and a better long-term outlook financially. And this cuts across all school types. More prestigious schools = R1s and elite SLACs (and most R2s are quite safe as well depending on what constitutes this category of school.)
Where it gets muddy are the very many schools that aren't that elite. These include large universities as well as small colleges, private and public.
While I agree that rural schools tend to have more trouble moving forward in recruiting students as compared to suburban & urban schools, the schools in urban/suburban areas also have higher costs to contend with due to their locations. One thing to know about a rural school is that they will use far fewer adjuncts, and will staff their gap courses with visiting professors (with full loads) instead. Or they'll strong-arm faculty into teaching overloads. This is good for the students—having lots of adjuncts is very bad pedagogically due to issues of continuity, face-to-face interactions, etc. It's also good for faculty in terms of sharing service and advising duties. But a school with the ability to switch to adjunct mode in a crisis (i.e. temporarily not replace retiring/leaving faculty) is in a more flexible situation than a school that will never find local adjuncts under similar circumstances and has to pay someone a real salary to be there. One reason small rural schools are vulnerable is that they don't have much flexibility if they hit a hard patch. But to be clear — large schools sometimes are suffering heavily with financial issues. It's something to look into on an individual school basis.
In terms of your decision, you say the college seems excellent. If it is really excellent then it might not matter that it's also rural.
