J.T said "Whichever manual it is to which you refer should give you some appropriate guidance.
If there is no other guidance run the calcs again either
(a) for incremental increases in TOW until you get a speed schedule for which V1 is not less than Vmcg. For a ferry flight situation off a normal length runway, this will fix the problem very quickly. "
Do you mean use artifically high V speeds by using a higher weight for the calculation, or do you mean increase actual TOW by actually loading more mass ie fuel ?