Level 20 before death wolf

I have three starterwolves (the two you create at the start + a third one I made in the customizer immediatly after)
I want them all to be immortalized, but not before they have reached level 20. Problem is, since they're my starters, they're getting up there in age... And I fear then might die before even reaching level 20.

The customized one is already level 20, he was a scout from the start and he's now a hunter to gain extra stats just because.
I'm also fairly confident I can get my lead to level 20 before he dies.

But the third one... He was a pupsitter first, then I wanted him to level faster so I made him a hunter, and now he's been a scout for awhile.
I'm sending him to the Glacier all the time (as often as I can during the day (even when I am at work I sneak in the time to send him out.) He's quite literally on the job 24/7 except when I'm asleep), because Wisdom is his lowest stat, and that biome gives the highest XP. 
But at 5 years and 10 months, and only around 7% XP increase per scouting, I fear his time will run out before he reaches the highest level.

Is anyone here good at math, has a better understanding of stat gaining, and is able to help me figure out if it's possible for him to even get to level 20 before he's send on his way to my Dynasty?

honestly without the use of guarana, I'd say .. probably not. I don't have how much exp each level requires, and exp can vary on average per scout. but just looking at it, I wouldn't think so.

on average he'll probably be getting around 1.2k of exp per scout. for his current level, you're looking at 16 scouts to reach level 15. I'm unsure how many times you send him out as a scout per day, but ofc the exp goes up each time you level up.

to get to level 20, you need to earn 40k exp, or roughly around 33 scouts or so. I can say it took me a week.. possibly? to get my scout to level 20 and I was sending him out every chance I got (but admittedly I wasn't using timers so I wasn't the most efficient).

I have checked how one of my past scouts was progressing in Glacier and compared data to determine how much scouting has to be done to max out your scout from the current progress.

From the point I see, your scout is 14 and needs 16725 EXP to level up. My scout gained 1044-1190 EXP when done scouting at this level. It'd take 15-17 scouts to level up.

When my scout was 15, 23725 EXP was needed to level up. Experience gained from scouting was 1137-1288. It must have taken 19-21 scouts to level up.

At 16, 28772 EXP is required. Experience gained: 1208-1352 per scout. 22-24 scouts to level up.

At 17: 34491 EXP is needed. My scout gained 1273-1447 EXP from each scouting. 24-28 scouts had to be done to level up.

At 18, wolves have to gain 40924 EXP to level up. Experience gained from scouting was in range of 1355-1491. To level up, 28-31 scouts have to be completed.

Wolves at 19 level require 48113 EXP to max out. 1407-1584 EXP is how much my scout gained after scouting done. To reach max, scouting must've been done 31-35 times.

Counting it all, in the most optimistic scenario you may have your wolf maxed out with 108 scouts sent, but it's really unlikely and you'd have to scout more, but not more than 135 times. You have 38 rollovers to do before your scout risks dying of old age. If you're capable of sending your scout 4 times per day, you'll have your scout reach level 20.

Also, nobody has mentioned this, but you can’t immortalize your lead wolf. Leads go to the dynasty when they die/are replaced. There is currently no way to make them immortal.

@Bad Wolfittude Oh! I had forgotten about the Guarana!! Somehow it completely slipped my mind that it's usable on other wolves as well. I've only ever used it on my lead, and forgot that it's not only for your lead. XD

@Dżanek Thank you so much for the calculations! I'm relieved to hear that it is possible for him to reach level 20.
I'm pretty sure I'll be able to send him out at least 4 times a day, but I'm going to stock up on a bunch on Guarana as a back-up. The plan is to keep sending him to the Glacier as it is one of the harder biomes and Wisdom is his lowest stat, so I want to at least get that even with the rest of his stats.

@Werewolf! I know that leads can't be made immortal, but I am holding out hope that it will be possible some day soon. Either by retirering our leads out of the role to a simple pack-member, or getting the option to make them immortal when they die, or maybe even retire them without killing them so they become a normal wolves that you can make immortal.
There are several threads already, suggesting to be able to make leads immortal so if you want to support us sentimental players, please give your support in those threads! ;D