Take my time during undergrad or get out as soon as I can?

I have spent a great year at a local community college (in Ohio), and combined with some summer credits there and credits from high school will have virtually all of my general curriculum done and most first year/some second year stuff. My planned major is Chemical Engineering.

I guess one detail left out is how I'm going to pay for my university education (transferring this fall). I have always enjoyed math and I have come to enjoy physics, chemistry and am interested in engineering as a career thus my planned major. Given that I have a two year degree right now I should be able to finish the curriculum in 3 more years. However I would like to take an extra quarter or two during summer + an extra year to pick up a double major (Math) and hopefully pick up some more research or internship opportunities.

I haven't received all of the info pertaining to my financial aid but from what I've read it probably won't be very generous and I will likely have to take out a substantial loan anyway. Would it be worth it to spend so much time and money on the undergrad level or just finish it in 3 years (would likely still have time for internship)? I would like to eventually (not immediately) go to graduate school for either major (math, chemical engineering or similar) and one motivation for the math major is that I would also like to teach part time at a community college but with a masters in Chemical Engineering or similar I may still be able to teach some classes depending on the individual college and how many other qualified professors they have hired...