Every time I put new pads in, I can’t get the disk to go between them.
What do you mean by “every time” ? When did you last do a full bleed?
Given the weather why not do a full bleed and clean your pistons as well – even mineral oil need the fluid changing or it gets pretty dirty and will eventually cease the main piston.
I use one of the crap “XMAS gift” plastic tyre levers to push back pistons. Obviously easier with the bleed open at one end if it is sticking though used a closed spanner carefully when its been in my hand (like for undoing the bleed valve)
There is a Park tool piston cleaning video… get the calipers moving smoothly and evenly then put the bleed block in (or measure something to use)
Hopefully after that you just push them in within the reservoir space and don’t need to keep playing with fluid levels..