H1B amendment and extension approved without i-94

[Ram-H1B]

I am working in USA and holding H1B Visa. My employer submitted H1B amendment and extension on last year. It was approved without I-94 and it's valid from Feb 13, 2019 to Apr 30, 2021. My current visa and I-94 are valid till Sep-2019. I would like to know the followings,

1. When do I need to leave from US and re-enter to get new I-94? is there any grace period?

2. Do I need to go back to home country (India) to get stamping or I can cross border from Canada/mexico to get new I-94.

Please assist on this.

[BornChampion]

You will need to leave a day before your I-94 Expiration date. You can go cross border or home country for Stamping, please note if you get stuck by any means in cross border country then you might be in a different situation as your passport might not be with you if taken by embassy or you might need to submit post 221G.

[Ram-H1B]

Thanks for your response. I am planing to go to Canada and re-enter. Can I cross border by air to extend my 1-94? please advice