Do you have a groom at the yard that could hose them during the day?
We have a paddock with a little bit of a dam. It is less than 3' deep. The horses go in there when they want, paw the water and many will lie down to wallow.

I am impressed at your dedication to ride. I have no motivation at the moment. Sometimes I will just go the stables in the afternoon, take Moscow out of the stable or paddock, and let him graze. Tacking up and riding feels like a mission. And I'm getting bored of going around in circles, merely working on a perfect trot with the occassional canter when I get the feeling he may actually not lose his marbles.
I have a friend's youngster I am working with. He is 2 years and 3 months approx, and all our work is groundwork (I have sat on his 3 times with someone holding or literally me just sitting there for 3 minutes while he figures out what is going on.
He's too young to be backed as such. But I am enjoying the groundwork and slowly adding in more advanced things, like us currently working on the bow.