well crud, thats no good, i have done that but mine was in a creek, so my suggestion for getting around that is a wheeled machine with bar tracks, i bought my set to feed hay with in the winter as it gets DEEP around here and i didnt have a 4x4 tractor - i have only been stuck once with my bar tracks in a creek as i sunk it all the way to the top of the tracks and when i came back to get it, it was over the seat i the cab it was a sink hole of some sort and i almost lost my entire machine. I have been stuck where i couldnt move but with the bucket pushing/pulling/lifting i could get myself out or hooking a chain to a tree and using the bucket to articulate myself out. Bar Tracks on a wheeled machine are unbelieveable, i have amazed myself where they will go even with the extra weight.
I my machine is 90hp and weights around 8000lbs before the tracks or 84" tooth bucket so its pushing 10K id say. I realize the Kubota is im thinking 12 to 14 so its a bit heavier but thats a drag getting stuck. I loathe the thought of wallowing around and trying to work in it with a tracked machine its very very frustrating from my experience. Try using a bar tracked machine and see what you think, I like it so much better i can work when my cousin calls n says its too wet my machine wont go. He has an ASV RT100 i think something like that its got the same perkins mine has but with a turbo.
AS for the doors and type you can have your roll up door those are scary, have one get jammed on you and try to get out!!! the only way is up/out the back window and try crawling up/out of there with the engine on fire!!!! a swing open door is there and easy to go through when the engine catches on fire, ask me how i know these things...........and yes its scary - my neighbor got stuck in a rental kubota with the roll up door and luckily it wasnt on fire and he had to crawl up/out of the back window to get out, he was trapped in it for 20 minutes before he got the back window popped out and got up/out of it. he didnt have his phone with them to call for help. I cant imagine trying to get up/out of it with teh engine on fire. Now another kubota roll up door incident, i rented an SV 75 for some demo on a neighbors burned house, i had the door up above me in the cab so i could hear someone giving me directions on maneuvering. I drive over the 6 inch curb wall and when it went over the door above me shattered and dumped glass all over me, down my neck/shirt etc.... i guess the torque/twisting of hte machine going over the curb wall caused something with the cab/door to get in a bind and it shattered it was an scary experience as i thought something fell on me - so i will stick with the swing open door i can kick the glass out and im gone!!!!! praise the lord for that - the rental place was angry with me like i did something wrong to their machine and i said yea i love glass shards raining down my neck, luckily i only had some small cuts, they made me pay for the glass/labor to the tune of 800 bucks - i never rented another machine from them or a kubota