V1 is for Stopping OR Going. In a Balanced Field scenario, Stop and Go would have the same V1, the same limiting weight, and the same Stop or Go performance.
If the Clearway is to be increased without a commensurate increase in Stopway, we are obviously no longer talking about Balanced Field, and the RTOW will be the lesser of the Accelerate-Stop, or the Accelerate-Go limit.
So, to answer the question, if the Takeoff WAS Accelerate-Stop limited, there would be no change in V1 or the RTOW. If, however, the Takeoff was NOT Accelerate-Stop limited, higher RTOW would be possible with a commensurately increased V1. (It would also allow for reduced V1s at the original weight provided that Vmcg etc. did not get in the way). In re-working the increased TODA case, care must be exercised to not 'bust' the Accelerate-Stop limit for the lesser ASDA at the higher weight/s.