It might be possible in principle, but therefore you'd have to install Galaxy locally because the public instance will never allow you to upload 80G. Given that this would be more complex than to install Samtools and you might have to install Samtools in addition anyway, I'd go with Ketils advice.
Edit: please see comments below, it is possible to use 250GB. Unfortunately, I didn't find a tool that would allow to run samtools view with the given parameters to filter by chromosome, it might be possible somehow (e.g. by installing a new tool, or building a workflow bam2sam-> filter data -> sam2bam, would be very inefficient and use up 250 GB ) but I didn't find how that would work.