Assuming that you are an American with little or no prior language learning experience, you may want to adjust your expectations.
It seems like you will have ~75 hours (5 months at 0.5 hours per day) of study by the time you leave. That should get you to a basic beginner level (CEFR A1) -- maybe A2 is you are really good. 5 months of full time study might get you to a minimal level of professional competence (CEFR B2).
https://en.wikipedia.org/wiki/Common_European_Framework_of_R...
Of course, if you speak a language that is linguistically closer to German and/or if you have learned foreign languages before, then the expected time to reach a level can be shortened.
Regardless, I encourage you to keep your expectations reasonable.
If you have any questions, I will be glad to answer. This is an area in which I have quite a bit of theoretical and practical knowledge.
The CEFR seems like a great reference point though that I wasn't aware of so that could be a great more objective measure.
We're hoping to add a few shows/ podcasts to our regime this summer to get our ears more accustomed.
That's at least what is helping me with Swedish.
Realistically if you want to get to at least a B2 level you are going to need much more than 15-30 min daily, even more because you aren't immersed in the culture and German is, frankly speaking, a quite hard language to learn. Sentence structure looks quite foreign if you only know English, grammar is complex, you have 3 different genders, etc.
Not trying to discourage you, much the opposite, go harder and you can do it but be realistic about it.
Try to focus on shows/podcasts that target children and/or teens -- the language will be more at your level. There may be more slang, but that will be relatively simple to navigate via various language forums.
Once your ear gets tuned to listening to native-speed German, then you can move on to more adult-oriented topics (start with simple, fun stuff and then move on to material that covers "real" topics).
While I am not a freelancer, I happen to work with one (he's mostly doing Django for my startup). He's originally from London, happy to connect you if you'd like to get first hand experience.
You can find contact details on my profile page.
If you've pulled off a similar feat in the past, do you have any language learning tips?
"Shoot for the stars, so if you fall you land on a cloud. - Kanye West"
Are there any good resources people have used for finding freelance work internationally or that are even specific to Berlin/ Germany?