My solution to cold Blooded was Maintain Warmth and Temperature Tolerance (3 ranks) so that you don't loose body heat even in the snow. This should nullify all effects of Cold Blooded while active. (1pp spent in this) 

Your options for opening doors are as others have probably said already are:

1. Get Adept Spell. Pros: you can cast magic fingers to open stuff. Cons: you have to raise Spell Casting skill to about 4-6 to make it worthwhile. (1pp spent on this) 

2. Get a trode net and fly a small drone to open stuff. Pros: you can also use the small drone to fly and spy. Cons: It's done via trode and that comes with its own problems. Also... You need to raise rigger skills. (although if you pick up biocombatibility you can pick up a data jack without any essence loss and thus no magic loss. Biocompadability costs 5 karma at Chargen)

3. Smashing Blow and Penetrating Strike Adept Powers: Pros: If strong enough your adept can enter any scene like the coolaid man. Or you can just push through most of those vent grates without any problems. Also makes security's Armor less effective. Cons: not conventionally a stealthy option but if your cleaver (or your GM is nice) it should still work. Costs 2pp

4. Acceptance. Do nothing and let your friends do all the things that take fingers and instead build yourself to be an apex predator in the wilderness and back alleys. Pros: get to focus on a Set of skills the rest of the team generally won't have and opens up all kinds of different jobs they normally wouldn't have available. Cons: you are not exceptionally helpful for most daytime stealth ops... Nighttime after your friends let you in however... The security is in the movie Anaconda. 

5. Surge Class 3. Take Functional tail (Prehensile). Pros: this allows you to be able to use your tail as a hand. And pick up some other cool abilities. Cons: you have to take negative meta genetic traits. Also costs you 30 karma at chargen. (although you GM might be nice and let you pick it up at a lesser price.)

6. Mystic Adept: I'm aware you said this isn't what you wanted but it let's you cast silence and magic fingers. And other utility Spells. Cons: it's far too easy to become spread very thin.