Here's a rough timeline I've come up with based on the studying about lengthening that I've done so far:
You don't say exactly when in january but let's say by the time you get everything booked and the surgeon is ready to go it's the 15th:
It's usually almost a full week before you start distracting after surgery, so that's the 22nd. 1mm per day is the maximum most recommend, if you run into soft tissue problems you'll either have to slow to 0.5-0.75mm, or just day days off outright. Let's say you run into a few small issues and take a handful of days off and your lengthening rate averages out to 0.8 mm per day. That rounds up to 63 days, or the 26th of March to reach 5cm of added height. All goes well you will not need to see any doctor other than X-rays until about a year later to remove internal nails.
Reasonable consolidation to start being near full weight-bearing on the leg would be an additional 3-6 months depending on a number of factors. Any complications depending on severity could increase this by several months or even years. For your typical surgery with no major issues you could certainly be getting around with crutches by mid-april.
You always have to factor what if though. There's no way to guarantee even a typical result. Please consider the following worst case scenario:
You have a complication or several, are completely bed-ridden needing assistance and you're in and out doing corrective surgeries. You are in extreme pain without pain killers, and your brain is so foggy from the painkillers and in general you just feel absolutely horrible and there's no way you can go to work even if you can work your crutches. Can you...?
Take the time off without losing the job? Upwards of 6-12 months for extreme complications, maybe even more for multiple extreme complications? This will be highly variable on your age, what happens to you, surgeon skill, etc. Way too many theoretical variables to give a time frame.
Will you be ok financially regardless of losing the job or not, for this length of time?
Be able to afford corrective surgeries that may spring up, in the 6-figure range absolute worst case scenario?
Using precise 2 on femur and doing a modest 5 cm certainly gives you the best possible odds of a quick recovery using a good surgeon...but again, you cannot guarantee anything and horrible things can go wrong when you break both of your leg bones and stretch them apart. So please be aware and prepared just in case. Best of luck.