A 3rd DUI within 7 years is a felony which carries a minimum 1 year in prison. Separate from potential defenses, you may be eligible for the diversionary program which keeps you out of prison and reduce the felony to a misdemeanor conviction.
It is unlikely that you have a negligence claim against your neighbor since you consented to ride the bike. The only other cause of action may be against the manufacturer for a possible defective throttle although you would need to have it inspected shortly afte the accident. However, your med-pay coverage may statisy the medical bills.
Based on your injuries and without knowing whether you need future surgeries/care or whether you have a claim for loss wages, it appears that a jury verdict will not exceed the $1M policy limits. However, if you do exceed the policy limits the defendant may very well voluntarily contribute to avoid a trial and subsequent collection efforts.