As a knowledgeable non-veteran
6 weeks off will be problematic. In general, most people will start to lose fitness after about 2 weeks.
Doing other activities will help, but both physically and mentally cross-training doesn't actually wind up working well. One problem triathletes have, for example, is that it's difficult to really specialize in 3 different activities at the same time. If you are spending lots of time in the gym on an exercise bike and the elliptical, though, it won't be so bad.
One positive thing about taking a break, though, is that it can help you avoid burning out or overtraining. Still, I'd probably limit the break to 2 weeks if possible.