We were fine with Tena overnight but a heavy wetter may need a premium product (tranquility, attends, abena and others). You may be able to get samples from manufacturers or supply companies, try searching the web for adult incontinence samples. Do get a full mattress protector and several washable bed pads too, even the best won't always prevent leaks.
A poll on the forum concluded that doubling up with a regular pad is not effective because the pads have a leak proof backing, but you can buy booster pads that are made for this.
My mother found LivDry (Amazon) was efficient. She said it felt like her underwear. They were easy to manage when she feared she wouldn't make it to the bathroom and helped to preserve her dignity. She had no problem wearing them to med appointments. I would note though that I found all the incontinent products expensive; this one is no different. I also used a bedliner just in case. Eventually I spoke with her doctor about the bladder issue and he recommended medication which has stopped the problem completely.
Two Liv Dry and 2 Poise pads work for my 92 year old mom. Most of the time the pads are full and the bed is dry. I have pads down on the bed as well. She goes to sleep around 9 and up around 6:30. All those products are on Amazon.
Prevail products. Usually must order from medical supply company, but worth it. Sometimes a local pharmacy will carry them. Walmart, Target, and the like - products are too small and don't really do the job.
I bought Tranquility over night diapers as well as Tranquility pads and used both at night. They worked out well. From Amazon. During the day used others that were less expensive and heavy as my Mother could get to the bathroom.
We use the Pure Wick System as well. It is expensive, but the money you save avoiding bed sores from Depend like panties is well worth the cost. Plus depending on the price of the incontinence product and how many are used per day it can be less expensive.
These conversations from the may be helpful
https://www.agingcare.com/search?term=best+adult+diaper
https://wellnessbriefs.com/