Well... realistically I don't really know anything about this. Plus I'm not in the U.K. So I'm unfamiliar with the educational system there. However I did go to college myself many years ago. So I thought I would simply offer some general thoughts with regard to your post.

From my perspective, I think the first thing you may want to consider is what your objective is in going to college. Are you doing this to enhance your employability, earning potential & potential employment "environment" (the type of situation you work in... for example in a professional atmosphere as opposed to entry-level type jobs) or are you going to college primarily to "expand your mind", so to speak.

If you're going to college primarily to expand your mind, then I would think whichever of the two options you mentioned offers the best opportunity to do that would be the one to choose. (Based on what you wrote, it sounds as though that may be the Open University?) However, if your reason for going is to enhance your employment potential then, it seems to me, what's important to consider is which option is going to make you most attractive to potential employers in the future who employ people to do the kinds of work you'd like to do.

When I was young many years ago, & getting ready to start college, there was a myth in vogue that said... just go to college. It doesn't even matter what you study. You'll be set for life. (How completely inane that was.) So many of us went to college & studied things like English literature, history or philosophy. And upon graduation we found ourselves qualified to do absolutely nothing! So that's the potential trap I think you want to avoid; there again unless you're simply going to college to expand your mind & perhaps hone your writing skills with an eye toward becoming an independent creative writer.

Anyway... those are my thoughts with regard to your post... for what they're worth... if anything. Under any circumstances, my best wishes for great success however you choose to proceed.