Here's the bitrate table: https://avidtech.my.salesforce-sites.com/pkb/articles/en_US/White_Paper/DNxHR-Codec-Bandwidth-Specifications
Keep in mind these are listed in MB/s, so multiply by 8 to get Mb/s if you're used to that number. HQ/HQX in UHD 29.97 for example is about 6.2GB per minute, or 375GB per hour.
How much bigger depends on your source footage, if you're recording in say UHD 29.97 10 bit 4:2:2 at 400Mbps, then the DNxHR HQX version would be about double the size.
You can just remove the DNxHR proxies when done so the space isn't being taken up.