Couple of choices, some inexpensive, some not, some legal and some not so much. The search for better nighttime lighting is a bit like the search for a better riding gas coach. Start out with the low cost easy solution stuff first before working up to the expensive items.
Besides the updated wire did you add high amp relays? Check the volts at the lights with the coach running and the lights on and compare it to the volts at the chassis battery terminals. Your goal is to limit the voltage differential as much as possible. If you coach was designed for daytime running light (DRL) check with a meter to ensure the circuit is switching correctly. You could be losing some volts in the circuit so an eyeball check might not be enough.
Many a coach headlight assembly are repurposed from other vehicles. If the assembly lens is starting to fog might be time to consider replacing. On the front of the lense is a DOT number that can be cross reference for a replacement assembly or maybe upgrade to the projector style aftermarket HID lights. OEM original replacements can get expensive while aftermarket may or may not meet original design specifications for aim and light diffusion.
You could try high wattage light bulbs. Try cross referencing the bulb number but this is where the not so much legal part comes in. Headlights are regulated to 60 watts, I think, to prevent you from blinding oncoming drivers. Blind a Trooper and you could be end up with a fix it ticket and maybe side of the road impoundment while blinding everyone else, well let's just say that would not be good for everyone. Also higher wattage means higher heat. Get it wrong and you could melt the light assembly internals.
Another option is the check and possibly correct the light aim point. Present day daily driver vehicles are also pretty easy but not so much with a coach that has repurposed assemblies. Get it wrong and again you'll be blinding oncoming drivers or limiting your own night time visibility even further than what you have now.
You could add additional lights but this can be tricky to keep the rig looking good and not so much something out of the latest Killer Zombie movie or something ready for the upcoming Baja 1000 race.
I really hate driving the coach at night because of the poor lighting. Highway driving isn't too bad but the unlit back roads to some parks can be an adventure in the dark. Decided the easiest solution was to time my travels to limit after sunset movement as much as possible or just slow down and use the high beams and fog lights when alone on the road. Whatever you do just ensure it can be undone easily in case you run afoul of the various vehicle lighting regulations.