Proposed immigration Legislation

Under current law, the initial unauthorized entry of an alien into the US is a civil deportable offense. But it is a one time offense; thereafter, the continuing presence of the alien (without more) in the US is not an additional offense. One of the proposed bills on immigration would change this to make the continued presence of such unauthorized aliens a felony. I wondered if then apprehended, an alien could then invoke the Fifth Amendment. Currently, the Fifth Amendment is inapplicable as deportation is a civil proceeding. Any thoughts?

Of course, interior enforcement by ICE is practically non-existent anyway so I suppose, the practical implications of any such new legislation  for the US interior are probably unimportant. In any case, if convicted of felonies, where will we find the funds to incarcerate a million or more of those known to be apprehended near the border?