Sliding Doors frozen shut on '04 Sienna

This is not the dreaded "oh shoot the cable snapped" or "oh shoot the latch motor failed" issue.

It's our first winter with an old minivan, and the dang sliding doors are frozen shut every morning with ice. Even the slightest moisture in the air does it.

Anyone here experience this and come up with a fix?

I think it's probably the topmost seal freezing to the door, and someone elsewhere on a terrible Toyota forum suggested using a credit card to break the ice. I may replace that piece of weatherstripping to see if it makes a difference. 

What kind of lubricant is best for soft door seals?

Silicone around the door seal once it warms a little and unfreezes.  

Some sort of silocone door seal lubricant should do it. Also is the painted surface that hits the weather strip on the door or the van? Either way, if you can get is somewhere warm and properly wash and wax that metal surface it will help to keep it free of moisture and freezing. When I drove rusty crap boxes in my youth the door jambs got more wax than the rest of the car. 

WD40

The WD stands for Water Displacement.  WD40 is not harmful to paint.  If you put some WD 40 on the painted surfaces it should displace the water and therefore displace what freezes.  

If you don't have a silicone lube handy, PAM cooking spray will work in a pinch.

I used Sil Glyde silicone grease when I lived where it snowed.

tried the silicone and it did't work, but maybe I just need to be more heavy-handed with it. I'll also wax the painted surface - good idea.

I've heard of Vaseline too for such.

I used dielectric grease on the rubber seal of my Land Cruiser sunroof and it went from sticky and temperamental to perfect just that quickly.

When I lived in Fairbanks, Alaska back in the 80's, we used Vaseline on the door seals and powder graphite in the locks and on the latch mechanism. Did that trick on the same truck (K5 Blazer) in KY/TN but didn't seem to help when the whole truck was incased in ice.  After chipping the ice around the door it would open easily though.

Had friends that used PAM cooking spray, it worked as well as Vaseline but you had to reapply more often. Probably better on the seals though being vegetable based and Vaseline being petroleum based.

Vaseline is probably going to rot rubber seals.

Honda has a Shin-Etsu silicone grease for exactly this purpose.  It's expensive, but gets good reviews: https://www.amazon.com/dp/B006Z9TZ9M/ref=cm_sw_r_cp_apa_VVv8BbKDWSD7S

Gummi Fledge is what I like for rubber seals, shin etsu grease is what I use on window tracks