Yes it is possible but at great cost
To do this you have to expend 2 (out of 3 per long rest) level 1 spell slots and 1 use of the channel divinity (once per long rest. it will also cost the use of 2 bonus actions to set up (1 for both thundrous strike and one for poison strike.
This means that he spends almost all his limited resources in one attack. So either he has to save all those resources for the chance to use them or he is out of options early on in the combat/day.
Also of note is that the max damage is 61 (or more if he has a STR mod that adds to the hit) the average is 35,5 = 5,5 (1d10) + 9 (2d8) + 14 (2d10+3) + 7 (2d6). This will be significantly higher if attacks with advantage as then the damage of poison strike changes into 20 + Paladin level. Resulting in an average of 44,5 = 5,5 (1d10) + 9 (2d8) + 23 + 7 (2d6).
On a related note is that he can lose the Thunderous Smite if he is attacked between the casting and his next hitting attack that uses it as it is an concentration spell. In opposition is that poison strike does not require you to hit but actually does damage to your attack target after you attack it hit or miss.
In conclusion yes he can have a high peak output but it is costly in terms of recourses and takes 1,5 turns (attack action + 2 bonus actions).
Chance of max damage
The chance to hit is as state in other answers very small. It is 0.000000434027777.. (0.000043403% or 1 in 2304000) to be more exact. This can be calculated by determining the chances for a max roll on individual dice. So a D10 has a 1 in 10 or 0.1 chance a D8 0.125 and a D6 0.16666...
If the Paladin attacks with advantage this chance becomes 0.0000434027777.. (0.0043403% or 1 in 23040) as the chance is removed from the poison strike.
And also remember that in all these case there is an equal chance of doing minimum damage which is normally: 10 (28 when attacking with advantage).
Play test Material
An important part of this damage is the damage by poison strike which is an part of the Oath of Treachery material which is currently only available as UA. As it has not been added to official material and has had no revision we can assume that there are balance issues with this ability.