Possible Clues:

• That's how much one can get in there- 2x10
• Degree - amount - scope
• How much the camper emerges
• That's the whole of it, and it's about 2 x 10
• How much does the camper get out of his shelter
• Area (of something)
• Is that how much you may get out of what's pitched?
• Area of former accommodation
• European vote a result of canvassing reach?
• Perhaps come as much as this out for the camper to start the day