I think it really depends on how well you do in your final exam...
2 of my friends who scored raw 44 last year aced all their sacs (by ace I mean getting 90+s with a few 100%s), however, they didn't do as well in the exam (I'm not sure what exact mark they got) and hence they 'only' got a 44.
On the other hand, there's this girl (she graduated last year so I don't really know much about her) who didn't do super well in her sacs (my friend told me she probably wasn't even ranked the top 5 in her class) but she ended up getting a 48 just because she absolutely smashed her exams.
Also, it's important to note that all sac scores are subjected to statistical moderation so getting a 80% in your sac doesn't mean you will get a 80% for your final sac grads (it all falls down to your individual ranking within your cohort and how well your cohort performs in the exam here)
I'm doing geo this year too so I don't really have that much experience in answering your question (first of all I have NO IDEA what ss am I gonna get, secondly I don't know what does 'hard' mean since it's very subjective...).So, to conclude, I don't think it will be ImPossiBLe to get a 45+, but I think you just have to do your best and AIM HIGH for it (I know it's vague too sorry!) Also, if you're really desperate to predict what ss you're gonna get you can check out the deakin raw score calculator here (
https://atar-calculator.deakin.edu.au/raw-score-calculator/)
All the best:)