A handy person who searched out quality fixtures and lamps could easily DIY a complete system for not a ton of money. In my area, it's a growing market. I have a family business designing, installing, and repairing landscape lighting systems.
I would just cap it at both ends and leave it in the wall. It's just a chunk of wire at this point so there's no need for additional info in the off chance that a future homeowner finds it.
I second the Caseta endorsement. I have tried most of the other brands and had various problems. Caseta costs a bit more than others but has been rock solid from day one.
The law says you can't sell an opener retail or wholesale if it doesn't have a B/U. Nobody can (legally) buy a new one that isn't compliant so by default, you still need a b/u even when you have a whole-house b/u (unless there's an exception I missed)
I've used a couple of these with baseboard heaters and with forced air wall heaters. They're great. Works with Homekit too if that's something you want.
It might be worth looking into getting a 120v power unit for the lift in the future. Most lift companies offer 240 and 120 options so it should be straight forward to source and install.
For landscape lighting, I regularly use Ideal wire nuts with a bit of white lithium grease squeezed in to keep water out. We have systems that have been in regular use with these connections for more than 20 years. They're easy to install, almost never fail, don't make a mess and any excess...
On the up side, if the WH is big enough and the power interruption short enough, you might be able to stretch out the hot water in the tank through most of the crisis.
Assuming you have not already bought the new Speed Queen dryer, I would replace the breaker with a 120/1-pole breaker, put a 4x4 box on the wall in place of the old 3-prong dryer outlet, put in a standard 120v receptacle with the correct cover and replace the dryer with a heat-pump unit that...