If the probability is high, I don't think there's a problem with betting above-average amounts, but make sure you've considered the risks involved. Even with a high probability of winning, there's still a risk.
If I were in that situation, I would do the same, but instead of betting all my money, I would bet by increasing it by 30% to 50% of my usual bet. That way, I'd have some money left over to cover living expenses for the next few months.