Couldn't you deal it with a plastic sheet. I'm pretty lucky as mines in a garage with central heating !!! Even got a fancy rad box cover lol !!!!
Wouldn't like leaves & snails all over me tank I'd feel like me water was dirty yukkkkk.
I'd have to buy a small metal or plastic shed/ container things put some insulation in it and put tank & ro in there !!!!👍✔
PIC BELOW !!!!!