Yes, the concerns about welding gas being closed is just wrong as CO2 is also used for sada and beer and that beer is often considered and essential service! Construction and repair are both often considered essential as well, even in the most forward thinking areas, it is important to keep things like power plants repaired. Even Bass Pro shops are open in the states which are the last to get the idea.
I would think that tank was a valuable item as they go for about $50 in the Central Texas area as I would guess that to be a 20 or 20C tanks. With the red color, I might also guess it is from a soda lifetime, as Coke and have specific colors.
So how to deal with an expired date? Depends on you and how your area deals but in my area, I take tanks in and swap at the welding gas suppliers as the best price and service combo. The place I go considered the hydro test as just part of doing business and doesn't worry the $25-50 fee that other places charge. That's why I do business there, they treat me right!
Some calling or even better, taking the tank in to let them see it is looking okay and asking will get the true story on each place you might shop.
One thing to keep in mind is that we are often not charged for the amount of gas we get but a basic charge to cover the labor and then a small addon for a few extra pounds of gas. I might go talk to some folks, be honest, and see how they feel about a simple swap of 20 for 10 or 5 as it will be much cheaper in the long run to fil a 5-10 than paintball. In this area the paintball folks get robbed as they charge per pound of gas and it is high!
You will soon regret the trip through DIY as it is nearly impossible to keep it stable for long. And who does it while you take a trip? Just not worth the messing and fumbling to get the education as there is usually NOT any right way to do it for long term fun.