awwwwww that's wonderful! Hope y'all have a ton of fun! You deserve it after all you've been through.
well I see Mike and Iffy have you covered. As long as you're not sub ohming those pannies will be fine. But.....I'd definitely get a multimeter to check your batts, and you can also use it to check ohms. With a mech, you're using the top portion of your battery charge only, in order to make your watts. I use a thing sort of like this Green DC 0 30V 2 Wire LED Display Digital Voltage Voltmeter Panel Car Motorcycle | eBay and when the vape drops off, I check to see if the battery has dropped below 3.9 if it hasn't, then I look for other reasons why the vape is weak. Such as, it might be arcing. I'd go check out some threads in the mech mods forums, cuz there are some things to learn about using mech mods that are much different than using regulated mods. Congrats on your prizes!
Curious I am ... what's the Ω's on your coil builds. I like mine around 1Ω to 1.2Ω on a mech. And I usually find myself swapping batts when they drop to 3.6-3.7volts. Sure - not as 'strong' a vape at that level but still decent. I'd constantly be swapping batts if I changed them at 3.9 volts.

had to dig it out of the closet and watch a few Youtube videos on how to use it.
) You don't want to run them below about 3.2, but even in my regulated mods I usually swap them out around 3.6ish. Probably in a mech you'll see some degradation of performance around that voltage, since there's no electronics to maintain the desired power level