I'm sure most people will say NO and be horrified to even think about the idea
but I am not among them.
I was told, by people on here, I would fall over and die, using thermal just even to WALK on my land. When I got my first head mounted thermal, a Q-14, back in Sept 2015, I was actually nervous, and spent several nights taking short walks outside at night, near the house. But I didn't fall down and I didn't die.
Since then, I think I've had every head mounted thermal we can buy (except some of the chinese units) and I am still above ground. And I roll around on my 4 - wheeler at speeds in the ranges you mention. I will say familiarity with the land you're rolling on matters. On un familiar ground, I'd be going slower and I've touched 30 mph (per the speedometer on the 4-wheeler) on my land. The land around here has a lot of gulley's and falling into a big gully would be no fun. Twice in 6 years, I've bumped into a fence (barbed wire) I didn't realize how close I was to, so be careful near fences. I was moving along side the fence and scrapped it, didn't crash head on into it.
I have both a 14 and a thermal up there usually. There's a pipe bridge on my land and on the N side of the pipe bridge, its a 20 foot drop off and on the other side a 10 foot drop off. Its really dark in that area and on some nights the 14 isn't enough to see the gravel (farm) road that goes across that pipe bridge. The thermal almost always can (except in Snow or Ice) so the thermal is safer in general on that pipe bridge than the 14. Other nights, if there is snow, the 14 can see better in that spot than the thermal, the luminosity of the snow is amazing, even in overcast conditions. NV truly "shines" in the snow
. So occasionally the 14 is better, but I rely on the thermal to navigate in general (and yes I know this goes exactly again the conventional wisdom, and I didn't say this for years, but I'm comfortable saying it now because I have no doubts about it any longer. I really do feel safer driving with the thermal on more nights than with the 14. Many more. Probably 90% or higher of the nights. Though again, I use both and feel even safer with both !
The main ford across the creek that runs diagonally across our land (250 acres) is in the woods. And on most nights, its dark in there (in the winter with a full moon, being the big exception where its very bright in there). But the thermal can see very well in there and in general better than the 14.
Do I ever go out with just the thermal on my head driving ? Yes. And in general, I feel safer with the thermal than the 14 driving, on my land due to the need to drive around woods, where things are very dark on many nights. The thermal doesn't care at all about dark, the 14 does. But I do take both, often. The main reason I wear 14s at night on most nights is so I can see the ir-laser on all my 556 and 762 "stoner" type rifles (the self-loaders designed by a group of people, one of which was named "Stoner"
). But as I've said, in snow and ice the 14 can often see better.
I'd sell the Axion and get a 14 ASAP, so you can have both up there. Once you have experienced hands free spotting while moving, you won't need the dedicated handheld thermals.
I've used
q-14 640
Odin 320
Patrol 640
Skeet 320
Coti 320
Snipe 640
Nox-18
Head mounted while driving ... and again ... I'm still above ground.
As to using a thermal at more than 1x while driving. I have done it. Again people on here said doing that even just walking with 2x, would result in death. But I've tried it and I'm still here. I wouldn't start out doing that. First of all, apparently some people have more troubles with thermal than I do ... and some have more troubles with thermal on their heads than I do, maybe there's something "wrong" with my brain
... but I have no troubles and I love thermal on my head! But just in case you're brain is different, start on on 1x and go slow. Walk around a bit for a couple of nights. Then try driving, and keep it slow, especially in confined areas or areas with obstacles ... build up your confidence and your speed slowly. Once you've built up your confidence and your experience, then try 2x standing still. Then you can try 2x rolling, slowly, etc.
But I don't recommend starting out on 2x at higher speeds, like 15+. Not until you have a body of experience at slower speeds on 1x.
And if anything ever looks "wrong" ... then stop moving. And be sure you are "oriented" ... i.e. that you know where you are and what you are looking at ... and that goes for NV or thermal. I've lost orientation a couple of times ... so be aware of the possibility and try to remember to stop and reorient if you think you might have lost your orientation (which way is which). And again, this goes for NV or thermal, driving or walking.
I've been doing this for years, with avg 10+ hours per week outside at night for 50 weeks a year, since Feb 2013 so 8 going on 9 years and 4000+ hours. I don't consider myself an "expert" ... but I'm not "just starting" either. And I know what I do works for me because I've done these things many times now in many different conditions. I do like going on unfamiliar ground, because its more challenging, but I do go slower there, for sure.
Best of luck with your attempts !!