Ice attacker

In the current meta ice type attackers are not particularly useful, so I would hold off on using TMs for them unless you have extras. I'd focus on any rock types you have until the legendaries go away. To answer your real question though, it really depends on how often you can do level 4/5 raids to get TMs. If they are hard to get, I would only use one charge on the lower IV lapras, if they are common, I would fix the higher IV one as well.

theres no bad answer here but here is some thing to consider and with as hard as it is to generate extra stardust, I usually wont even consider leveling a toon under 91%

1. you will really only have enough rare candy to meta level one legendary over the next 6 months...chose wisely
2. with dragonite not part of the raiding world and now not really a viable gym defender the value of ice has gone way down
3. its estimate in gen 3 that eevee evol. glacion will out perform lapras in all ice catagories and eevee candy is easy. its max cp is in the upper 2800's. about 100 cp behind arti. I already have a 97.8% waiting for it.