Any suggestions on dealing with night time urination issues?

Are you really using Depends or are you just using that term generically? There are other brands that are way more absorbent, sorry I don't have any specific brands in mind but I know this has been covered in the forum before, and there are comparisons on line if you do a search.

There are also booster pads that can be put inside the underwear, they absorb like pads but have no liner so excess can soak through to the underwear.

I was also surprised to discover that some places sell the bed pads in different thicknesses as well, I guess I wasn't paying attention when I bought ours.

My suggestion would be zero water/tea/juice after dinner. Only enough sips of water for her to take any night time meds. See if that makes a difference.

My Mom uses Tranguility Overnight pullups .. They hold a lot of liquid.. I buy them on Amazon.. Read the reviews..

Oops it's Tranquility.. With a "Q" not "G"..

I'm using the actual Depends but I'm definitely going to try other brands. So far though they've been the best ones I've used. Also cutting back on fluids before bed, in fact I already have but it hasn't helped yet. You obviously expect SOME urination during the overnight but this is beyond the pale. And not only is the quantity a problem, but lately Mom has taken to wrapping herself in her blankets during the night, like a mummy, so they end up getting drenched too, which makes even more laundry. And she has the annoying habit of stuffing handkerchiefs and tissues under her at night so it's even more of a mess. I mean I expect some mess in the morning, just not an absolute swamp.

Some medications contribute to nocturnal enuresis; check with your pharmacist and/or physician to find out if this could be part of the problem.

Does your mother have any cognitive impairment? If so, not completely emptying her bladder could be part of the problem. An autism specialist explained to me that often people with cognative impairment can misinterprete bladder signals in the brain. She said often they will only go enough to relieve the urge feeling. She recommended that once the person has finished peeing, leave them in place and count to 30. Then encourage them to try to go again. This will take monitoring on your part but if it helps, right? Also if you know mom is tossing and turning for a few hours, try getting her up one last time for a final try. My son has autism and bed wetting was a huge problem- he managed to soak everything on his bed, sometimes even his pillows! Extra Depends and pads were just wasted money. What finally worked was a combo of using the 30 second technique, getting him up for one more try if he's still awake when I go to bed and limiting liquids after 6pm. Best of luck - I know how miserable washing pee soaked bedding can be!

It sounds like her body is still producing urine at night either because she is not sleeping soundly or because it is not working correctly. Consult her Doc and ask about something to help her sleep instead of tossing and turning for several hours.
Perhaps a potty run at 11pm before you turn in? If she has been awake or dozing her body has been producing urine since she went to bed at 9.
Good Luck.