how long can i drive needing motor mounts

Hello, there is no good answer for this question. Because worn out parts should be replaced. If they are worn out, they were clearly cause other problems related to driving safety or other component where and premature failure. For example, if your motor mounts are failed, and put extreme stress on the rest of the powertrain. Such as axles, driveshafts, wheel bearings and other related components. If your control arms have worn parts, other suspension components can take additional stress and cause abnormal premature wear. So the answer is - you can't get away with driving. You're taking a risk, and at the end of the day, other damage and safety issues may occur.