Hello,
You can change the settings of your Surface so it will never go to sleep even if it's idle. Here's how:
Step 1: Using your Surface keyboard press Win+X, and then from context menu that appear in bottom left choose Power Options.
Step 2: In new window that opens up click on Change plan settings.
Step 3: In this new window, you can change the time that’s need to pass before your Microsoft Surface goes to sleep mode. Click on drop-down menu under Put the computer to sleep and then choose the appropriate time. In your case, you can choose "Never".
Step 4: Once you are done with these changes, click on Save changes button located in bottom right.
Let us know how it goes.
Regards.