I can offer some insight: Barbiturates if you had them would work WAY better. They depress the CNS until your stop breathing at enough doses. Benzos do not. They have a ceiling effect where more does not equal more sedation or breathing supression. Even adding alcohol and opioids can still be survived. Really depends but benzodiazepines alone have no way to kill you even at a very high dose as far as I know. I don't think Wikipedia does it justice either but here is what it says: "
Although benzodiazepines are much safer in overdose than their predecessors, the
barbiturates, they can still cause problems in overdose.
[20] Taken alone, they rarely cause severe complications in
overdose;
[171] statistics in England showed that benzodiazepines were responsible for 3.8% of all deaths by poisoning from a single drug.
[22]However, combining these drugs with
alcohol,
opiates or
tricyclic antidepressants markedly raises the toxicity.
[23][172][173] The elderly are more sensitive to the side effects of benzodiazepines, and poisoning may even occur from their long-term use.
[174] The various benzodiazepines differ in their toxicity;
temazepam appears most toxic in overdose and when used with other drugs.
[175][176] The symptoms of a benzodiazepine overdose may include;
drowsiness,
slurred speech,
nystagmus,
hypotension,
ataxia, coma,
respiratory depression, and
cardiorespiratory arrest.
[173]
A reversal agent for benzodiazepines exists,
flumazenil (Anexate), itself belonging to the chemical class of benzodiazepines. Its use as an
antidote is not routinely recommended because of the high risk of resedation and seizures.
[177] In a double-blind, placebo-controlled trial of 326 people, 4 people had serious adverse events and 61% became resedated following the use of flumazenil.
[178] Numerous contraindications to its use exist. It is contraindicated in people with a history of long-term use of benzodiazepines, those having ingested a substance that lowers the seizure threshold or may cause an
arrhythmia, and in those with abnormal vital signs.
[179] One study found that only 10% of the people presenting with a
benzodiazepine overdose are suitable candidates for treatment with flumazenil.
[180]"