A lot depends on the CODEC being used. I have about 20 installed, you could have more or less.

Most CODECs allow an overall bitrate, which you could set to say, 125k per second, which would always give you a 7.5MB per minute video. Then again, it cold be smaller based on key framing, or it could be larger if there is too much delta between frames.

Do not expect to just find a magic number and work with it, it takes a long time and a lot of experimentation to get quality output and a small filesize.

You spent $500 on Premiere, you should learn how to use it correctly. Read the manual again, then a few more times.