Glad to help Johnny.
A word of caution though. That extra weight your talking about will probably have a pretty big impact on flight dynamics especially at your altitude. The heli will most likely seem more sluggish and the added weight will also have an effect on flight time. Give it a try I guess, but I'm pretty sure your not gonna be happy with the adverse effects.

That said you're right about changing batteries. It can be a little cumbersome, but here's the way I see it. It gives the motors a little rest between packs. I know this really doesn't seem like a big deal with the 4-5 minute runs we get with the OE packs, but the 12-14 minute runs that li-po's give us can get the motors pretty warm.

Also since I'm on the subject of caution, be careful with the cheap Li-Po chargers. They're cheap for a reason. Do not leave them unattended during charging and check the Li-Po's temp during charging to make sure it's not heating up. If they build up too much heat during a charge the best case is the pack will be ruined and the worst case is a cell or cells may burst and as soon as that Lithium hits the air it will catch fire.

Remember,
it's all fun and games,
till your Li-Po bursts into flames.

Seriously though these batteries demand our respect.