You can collect dew by using a cloth to mop it from the grass and then wring the textile.
In Israel there is developed a Tal Ya dew catcher, a kind of funnel where a plant can grow in. Dew can condense on it and flow to the plant.
The Waterboxx is a bucket with a similar ribbed lid. The condensed water is fed to the plant roots via a wick. Also towels and sails can catch dew.

You can melt ice or snow. Melt snow in small quantities, you can add some extra after a while. If you do put much in a pan then only the bottom part melts. This creates an insulating air pocket and a locking snow layer. You face a risk that the pan melts before the snow does! You can also hang a bag or sock with snow next to the fire so that it can not burn or melt, but the snow can. Catch the water. You can even make a snowball as a brochette around a twig and capture the dripping water.
If you don’t have a fire, you can consider to melt snow using your body heat.

Dew : goodnight kiss to the plants. (Hugo Olaerts)
The problem with the dew is that it is too early in the day. (Susan Richman)