What makes you think you may not be insured?
Provided you had valid insurance cover at the time of the incident your insurers cannot refuse to indemnify you against Third Party claims even if you are convicted of driving with excess alcohol. Insurers are not entitled to void cover because the driver has broken one of the road traffic laws (with the single exception of driving whilst disqualified). If they were, every prosecution for, say, speeding, careless driving or excess alcohol would be accompanied by a charge of driving with no insurance. A visit to your local Magistrates’ Court on traffic court day will demonstrate that this is not so.
Provided it is stated in their terms and conditions they MAY reduce any payment they make for accidental damage to your own car if they have a clause that states they may do so if they believe you have been negligent.