What would your uncle tell you to do?
Your uncle would understand. Besides, funerals are for the living...NOT those that have passed on. Going or not will not bring back your uncle. So, I would talk with the other family members and let them know what is going on, should you decide not to possibly jeparadize your job. You can go by and pay your respects after work, if you wish.
As for your current job...You get what you settle for. If you can't afford the interruption in cash flow, then your decision is clear. Otherwise, take the chance and begin a search for a new employer.
Bottom line: Priorities...You have to take responsibility for U, cuz nobody else will. We can't always do what we would rather do, or do what others would rather we do. Anything we do has to be done in view of our priorities; if they're not compromised, then it is a matter of choice. Otherwise, we're kidding ourselves and will have to pay the piper...
You know what you must do...
P.