I will add that Scriv's once said that if you are facing a divorce or some other event where you could reasonably expect a 209A coming down on you (and he did imply that 209As are thrown around in places like MA during divorces like slurs), to get them out of the state and not just out of your possession. I suspect that would apply to other scenarios too like DWI, etc.
Strictly from a legal point of view DWI only comes into play if it is 3rd offense, and if you have 3 DWI's you are not really someone I want with a gun.. From the point of suitability, the C.O.P. can pull or deny your LTC/FID without a felony conviction, but on the basis you were arrested
Once a 209 is issued you have to turn in your guns, most of the time the cops are going to come looking for them if they know you have a FID/LTC. If your guns are out on loan you are going to have to disclose where they are if I had to take a guess and they will be picked up. I know in NH you have a year to transfer them to a non prohibited person. In MA since you no longer have a LTC/FID you can't sell them on a FA-10 to anyone assuming the cops will even let you transfer them without a court order. My best advice for anyone who thinks they are in a position to be served a 209 order in MA is to make sure the guns are gone to a trusted friend, and have FA-10's filled out ahead of time to be mailed the second the cops show up. It is a fine legal line as to the legality of this tactic, and since I am not a lawyer I can't comment on if it is legal or illegal to do it, but I have seen it done.
You can't transfer a gun to a friend out of state without a FFL involved, so the best you can do is to run to a NH friend who will rent you a room, go to town hall, register to vote, go get a drivers license, register and insure your car, change everything that would make you a MA resident to a NH base, then you can legally take the guns you lent your NH friend back as a newly minted NH resident. This is assuming there is not a 209 involved because if that is the case you can't get them back ever from anyone until the order is vacated, but at the second before the order is served you can FTF transfer them to a person known to you in a FTF transaction in NH
remember the second you declare NH residency your ma LTC is void, so make sure the guns are over the border in the hands of a trusted friend before you "move"