What I'm wavering on is whether to buy the $450 30-day bus pass which allows me unlimited travel for that period or be a bit riskier and hope I'll find enough rides to get me across for cheaper. I need to sit down and do the research and the maths really.

Interestingly, there are two ways to do this and I'm not sure which is better. The first is estimating a probability that you'll be able to find a ride across any particular arc, and then calculating the cost (and stopping and buying the pass if it's more than $450/(1-p)). The second is calculating the cost C, and then asking "is p>(C-$450)/C?" (Both assuming risk neutrality.)

If Ridejoy publishes any numbers about success rates, then the first is probably the better choice, but if you're guessing, it might be psychologically easier to do the second (though it also puts you at risk for anchoring).

I can rent a car for sure (I'm 31) but I haven't driven in ten years and considering it'll be December I'm not confident in my driving ability in bad weather conditions...

Wise choice!