Let's be realistic - 700 is a stretch.
680 is pushing it as well, but it is possible with a bit of luck on test day. Clearly you know how to target your weaknesses and improve upon them. (A 380 to a 620 is OUTSTANDING.)
The most important thing at this point is to focus 90% of your effort on the question types causing you to miss 300 to 700 level questions. (With just a few weeks to prepare, you are most likely not going to be able to internalize the strategy needed to quickly tackle
700+ questions in your weakest areas because you will need that time to internalize the strategy to tackle
300-700 level questions in your weakest areas.)
With some diligent work on CR, you can probably raise your Verbal to around a 38 or a 39 on test day. With targeted work on quantitative, a 43 or a 44 is not out of the question. A 44Q/38V would put you right around a 670/680.
So here's the point. Use the same study skills that have gotten you to a 620. You know how you learn and you know your weaknesses. Forget about 700+ questions at this point unless it is something with which you already feel comfortable. Trust me on this.
Get your 500-700 level question strategy down COLD, take the test, and go from there.
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-William Andrus Alcott