I can be comfortable and confident going inadvertent but I better shoot that approach as fast as possible and can’t even consider going missed or an alternate because I don’t have the fuel.
You're doing it wrong.
If IMC is a possibility, but you really don't have the fuel if you do need to go IFR, then why are you taking the flight?
What I tell our ops center:
1. That I don't have the fuel for IFR and I may only be able to fly the patient so far before they need to continue by ground (or maybe another aircraft).
2. I can get the med crew to the patient, but they will have to continue from there by ground.
3. I decline the flight for weather.