It could work with a smaller battery, but it's still pretty big.
I put my second battery there too, and used a junkyard washer bottle and pump from an import pickup back up on the firewall on the driver's side.
Don't have any pics at the moment, but it was easy to re-route the wiring and the plumbing and it worked great for many years.
In fact, as you'd expect the old import pump was even more powerful than the somewhat anemic Ford washer pump.
I noticed in a picture just the other day (and again saw it today here on the forum) that someone had an empty slider bracket mounted right there on the front of the driver's wheel well. I wondered if it was for an alternate reservoir.
I'm pretty sure all the different versions of Bronco reservoirs bolted straight to the wheel well, but the ones I like have a bolt-on bracket, and the reservoir slides over the bracket.
Good luck.
Paul