ThumperPup

Hi and thanks for taking the time to read this and if you can respond thank you
I have 2 questions
the first one is
i went to take my winter blizzak tires out of storage yesterday because i was going to have them put on today two had 6.5-7/32nd and two had 5-5.5/32nd however one of the ones with 5-5.5/32nd has holes in it and ****** from rats chewing is my best guess
I know that if i go to a tire shop and ask them to just replace one of them with that much diffence in tread they are going to insist and say they will only due it if i buy two new tires because these tires have a debth of 12/32nds so they will not allow me to go to a tire that has less than half the tread depth with a new tire
and i dont want to spend 400-440 for two tires that will proabably only get one winter season out of them because ill be moving down south probably back to florida next year in the spring so then ill have two winter tires with great tread and cost alot of money and have nothing to do with them anymore.
i was looking online and i could only find used tires that was sold in a single for my current size thathowever it has 9-9.5/32nd on it if i put this 9.5/32nd tire on the same axle as the tire with 5-5.5/32nd will this be ok ? or is 4 to 5 / 32nds way to much of a differnce in depth to be save ?

the other question is can i go wider on the rear and be safe? like i saw some tires that where 225 with and there where sets of two of them if i have 215/55/17 on 1 of the axles
can i put a 225/50/17 go wider and lower profile on the other axle i know it will chance the high of the car probably but not by to much
so im assuming the biggest issue would be the width
or a 225/60/17 ?
or 225/45/17

i also remember reading somewhere that for winter tires in snow and and ice that sometimes its better to go with a narrower tire at times but would it be save to have a narrower tire on the year? would i want to go down toa 205 ? for some reason going narrower sounds like a bad indea but not exactly sure

THank you much