Another solution if you intend to fight is to have some Treeguards (not just one) to help you in your fight.
A Treeguard is a tree monster that have a chance at spawning if you cut too many (Lumpy) Evergreen trees. They come in 3 sizes, and their stats (damage, walking speed, attack range, health) scales proportionally with their size:
- Short (they spawn from the tiniest trees, scale is 0.7)
- Medium (they spawn from the medium sized trees and look like adult tree, scale is 1)
- Tall (they spawn from the adult trees and look gigantic, scale is 1.2)
Between the beginning of the game and Winter, you have 21 days, and the Deerclops usually spawn around the 30th day, which mean you have around that much time to cut as many trees as you can to spawn Treeguards. Cutting adult Evergreen will allow you to retrieve 2 pine cones to plant 2 more trees. Repeat the cycle to have more trees to cut.
Whenever you spawn a Treeguard, don't kill him. Instead, lead him far away enough then start planting pine cones until the Treeguard forgets you and plants himself in the ground. Then return cutting trees to keep spawning more treeguards. The more you have the better.
Once the Deerclops attack, if possible, try to make it so the Treeguards are sandwiching the Deerclops (at least one out front and one in the back), this way he can't freeze them both, and one of them is still attacking him.
Upon doing this, 2 medium-sized Treeguards I had spawned, managed to kill the Deerclops "on their own"*, and they both survived.
*: I initially attempted to kill the Deerclops myself, but I had to deal with some shadows (because I had 0 sanity). Luckily for me, when the Deerclops chased me, he broke a tree, which triggered the Treeguards into attacking him. In the end, I barely attacked the Deerclops. So, in a way, the 2 Treeguards sandwiching the Deerclops managed to kill him alone.
If fighting isn't a solution, when I hear a "warning sound" from the giants, I run as far as I can from my camp (if I have one).
Once the giant monster has spawned, I leave him on that part of the map, this way he won't respawn on subsequent season (e.g. a new DeerclopsBearger won't spawn in the next Winter, if the previous one wasn't killed). You just have to make sure that nobody approach that part of the map (consider it a quarantine area), so he won't notice you nor your buildings.
Although doing that would prevent the Bearger from respawning, I heard the Deerclops despawns after Winter, so he would respawn on subsequent Winter anyway.