If speaking in the strange style where you separate each word, would you still attach these words together?
When I piece together sentences in other languages, it's perfectly fine to go slowly and say "in --- the --- drawer", where each word has a pause, and you think about the next word.
This approach would work in Russian, too, if you don't mind speaking like a teacher.
In school, in Russian class, teachers regularly do Dictation exercises. It's not uncommon to see them pronouncing the text word by word, including single consonant prepositions. For example, see these YouTube lessons (just some random results from searching "урок русского диктант"):
- for 8 yo kids, starting at 01:55. The phrase is "Мальчики Юра и Ваня идут в лес."
- for 11 yo kids, starting at 03:50. The phrase is "летом собачка пробиралась к даче".
Mind you, it's just as common to see them not make any pause in some cases. The first lesson linked above sounds like: "Юра -pause- иВаня".
Edit:
And of course, if you've suddenly found yourself in need of a carefully thought-out word mid sentence, of course you can pause even after the preposition and think:
- "Я ходил в кино с... ммм... эээ... одной знакомой".
That would be perfectly natural.